Ultimate Make-Ahead Christmas Croissant Breakfast Casserole: A Festive Vegetarian Delight

Imagine waking up on Christmas morning to the aroma of a delicious breakfast baking, without having to lift a finger. Our Christmas Croissant Breakfast Casserole is precisely that – a magnificent vegetarian breakfast casserole, meticulously assembled in advance. This means all you need to do is pop it in the oven come morning. Brimming with earthy mushrooms, vibrant red bell pepper, unique poblano pepper, and a trio of rich cheeses, this decadent croissant egg bake is destined to become a cherished family favorite and an indispensable part of your holiday breakfast traditions.

This website uses affiliate links. See our Privacy Policy for more information.

Effortless Holiday Mornings: The Perfect Make-Ahead Vegetarian Croissant Casserole

There’s something truly magical about holiday mornings, and they should be spent enjoying family, not stressing over complicated meals. This Christmas Croissant Breakfast Casserole is designed with that in mind. It’s an unbelievably delicious recipe that I’ve proudly made three years in a row, a testament to its appeal and ease. Now, it’s ready to bring joy to your holiday table too.

One of the many reasons I adore this particular croissant casserole is its vegetarian nature. It’s incredibly satisfying and rich on its own, delivering a full flavor experience without the need for meat. However, for those who prefer, it’s also wonderfully adaptable, allowing for the addition of various meats if you choose.

My philosophy for big holidays, when you’re preparing a grand feast all day long, is to keep breakfast a little lighter. Skipping the meat at breakfast ensures everyone has room for the many culinary delights to come later in the day, while still enjoying a hearty and flavorful start.

This casserole is already exceptionally rich, thanks to the croissants, cheeses, and custardy base. What truly elevates it are the unexpected pops of flavor from poblano pepper and fresh green onion, offering a delightful “zip” with almost every bite. Poblano peppers, in particular, are incredibly flavorful and add a subtle smokiness and mild heat that makes this casserole truly special. They are the perfect answer to the perennial holiday breakfast question, “What should I make?”

For me, the most beautiful aspect of holiday traditions, like serving this very breakfast, is the anticipation it creates. My family now eagerly expects this casserole every year, and it’s become a cherished part of our Christmas morning ritual. Similarly, on Christmas Eve, I prepare Christmas Soup and Christmas Cranberry BBQ Crockpot Meatballs (both convenient slow-cooker recipes), and these have also solidified their place as beloved family traditions.

The best part? All these recipes are designed to be easy. Because let’s face it, the holiday season is busy enough without adding complex cooking to the mix!

Essential Ingredients for Your Decadent Croissant Breakfast Casserole

Creating this festive Christmas croissant breakfast casserole involves a thoughtful selection of ingredients that come together to form a harmonious and incredibly delicious dish. Here’s a closer look at what you’ll need and why each component is key:

• **Peppers:** We feature both a vibrant red bell pepper and a subtly spicy poblano pepper. These aren’t just tossed in raw; they are roasted first to unlock their deep, sweet, and slightly smoky flavors, adding complexity and festive color to the casserole.
• **Mushrooms:** These provide a hearty, umami-rich component, giving this vegetarian croissant casserole a satisfying “meaty” texture and flavor. They’re so good, you won’t miss any actual meat, though the option to add it is always there.
• **Butter:** Unsalted butter is essential for sautéing the mushrooms, helping them achieve a beautiful golden-brown color and a richer flavor profile. It also contributes to the overall decadence of the dish.
• **Croissants:** The star of the show! Three to four large, buttery croissants, typically found in your grocery store’s bakery section, are ideal. Their flaky layers and rich flavor soak up the egg mixture beautifully, transforming into an incredible custard-like texture that’s far superior to regular bread.
• **Green Onion and Parsley:** These fresh aromatics add a bright, herbaceous note and a gentle oniony bite, providing a lovely contrast to the richness of the cheeses and croissants. The green flecks also enhance the casserole’s festive appearance.
• **Cheeses:** A luxurious blend of white cheddar, Swiss, and Parmesan cheeses. Opt for a high-quality, sharp white cheddar for maximum flavor. This trio provides a creamy, tangy, and nutty depth that perfectly complements the other ingredients.
• **Wet Ingredients:** The foundation of the custard – fresh eggs, rich cream, and whole milk. When combined, these liquids are absorbed by the croissant pieces during an overnight soak, creating the signature soft, custardy texture that makes this recipe so irresistible.
• **Seasonings:** Simple but crucial, just a touch of salt and freshly cracked black pepper is all that’s needed to enhance and balance the flavors of the entire dish.

Crafting Your Festive Croissant Egg Bake: A Step-by-Step Guide

You might wonder why this particular egg casserole is specifically dubbed “Christmas.” Just look at it! The vibrant bits of red and green pepper, combined with fresh green onion and parsley, create a truly festive and eye-catching presentation perfect for the holiday season. The colors alone make it a showstopper for your Christmas breakfast or brunch spread!

However, this dreamy dish is by no means limited to the holidays. Its incredible ease of preparation and the year-round availability of its ingredients make it a perfect choice for any brunch, potluck, or special morning throughout the year. It’s a versatile recipe you’ll want to keep in your repertoire.

Here’s how to prepare this delightful croissant egg bake:

• **Roast the Peppers:** Begin by roasting your red bell pepper and poblano pepper under the oven broiler. You’ll want the skins to be completely blackened and blistered. Once roasted, immediately transfer them to a resealable bag to steam for a few minutes. This makes the skins incredibly easy to remove once they’re cool enough to handle. Discard the skins and seeds, then chop the softened, flavorful peppers.
• **Sauté the Mushrooms:** In a medium skillet, melt the unsalted butter. Add your chopped mushrooms and cook them over medium-high heat, tossing regularly, until they are beautifully browned and have released most of their moisture. This step concentrates their flavor.
• **Assemble the Base:** In your chosen casserole or bake dish (a 13×9 inch dish works perfectly), gently combine the roasted peppers, browned mushrooms, chopped green onion, fresh parsley, and bite-sized pieces of croissant. Ensure the ingredients are evenly distributed.
• **Add the Cheeses:** Generously sprinkle the shredded white cheddar, Swiss, and Parmesan cheeses over the assembled mixture. This creates layers of cheesy goodness throughout the casserole.
• **Prepare the Custard:** In a separate bowl, whisk together the eggs, milk, and cream until well combined. Season lightly with salt and pepper. Carefully pour this egg mixture evenly over the ingredients in the baking dish, ensuring the croissant pieces are well saturated.
• **Refrigerate Overnight:** This is a crucial step! Cover the dish tightly with plastic wrap and refrigerate it overnight (or for at least 8 hours). This allows the croissants to thoroughly absorb the egg-milk-cream mixture, meld the flavors, and transform into that desirable custard-like texture.
• **Bake and Serve:** On the morning of, preheat your oven and bake the casserole until the center is set and the top is golden brown and bubbly. Let it cool for about 10 minutes before serving to allow it to firm up slightly and prevent scorching your mouth.

It’s as easy as that! What’s even better is you can prepare this casserole up to 2 days in advance, making your life even simpler during busy times.

Expert Tips and Frequently Asked Questions for Perfect Results

To ensure your Christmas Croissant Breakfast Casserole turns out perfectly every time, here are some helpful tips and answers to common questions:

I mention refrigerating overnight in the instructions, and while that’s ideal, this make-ahead croissant breakfast casserole can actually be assembled even further in advance. The key is to give it a good, long refrigeration period – at least 8 hours – because that’s when the flaky layers of the croissants fully soak up the milk, cream, and egg mixture, allowing them to become wonderfully tender and custardy. You can extend this stage to up to 48 hours without any issues, making it incredibly flexible for holiday planning.

I typically use a standard 13×9 inch bake dish, but any good-sized casserole dish will work beautifully. This recipe yields a generous amount, making it perfect for feeding a crowd during the holidays, a leisurely brunch, or a potluck gathering. As long as all your solid ingredients comfortably fit in the dish before you pour in the liquid mixture, you’re good to go. Don’t be alarmed if the casserole swells slightly as it refrigerates and the croissants absorb the liquid – this is completely normal and expected, though it won’t overflow.

As tempting as it is to dig into this delicious breakfast casserole right out of the oven, PLEASE exercise caution! Allow it to cool for at least 10 minutes before serving. Trust me, I speak from experience – you will totally scorch your mouth if you rush it! The cooling time also helps the casserole set, making it easier to serve clean portions.

My Christmas morning routine often involves retrieving this casserole from the refrigerator and letting it sit on the counter while I brew coffee and the family begins opening gifts. Once the oven is preheated, it goes in. We prefer a more relaxed, informal breakfast on Christmas, so having this ready-to-eat casserole allows everyone to enjoy a warm, satisfying meal at their own pace.

I’ve emphasized that this vegetarian breakfast casserole is assembled in advance, but can it also be *baked* in advance? Absolutely! The texture of this casserole is remarkably lovely and custard-like, which prevents it from drying out. So, if you need to bake it the day before, a gentle warming in the oven or a quick zap in the microwave for individual servings will reheat it perfectly, bringing it back to its delicious, comforting state with no worries.

Selecting Croissants and Smart Substitutions

When it comes to the croissants for this breakfast casserole, I confess I’m a bit unspecific about the exact quantity. My method involves picking up 3 or 4 large croissants (or perhaps half a dozen smaller ones) from the bakery section of my grocery store. Then, I simply use enough chopped croissant pieces until, when mixed with the roasted peppers, sautéed mushrooms, green onion, and parsley, the mixture adequately fills my standard 13×9-inch bake dish. Don’t overthink it; there’s no magic precise amount. I do plan to weigh the exact amount next time I make this croissant egg bake and update this post accordingly.

Now, in the event that croissants are unavailable or you simply want to try an alternative, what would be suitable? My top suggestion would be brioche or another rich egg bread. Their similar tender, slightly sweet, and buttery profiles make them excellent substitutes, yielding a wonderful texture. Other good options to consider include a high-quality challah bread, a sturdy country-style white bread, or even a good French baguette. Keep in mind that while these will also create a delicious casserole, the unique flakiness of croissants is part of what makes this particular recipe so special.

Optional Meat Additions for a Heartier Breakfast

While I firmly believe that this glorious holiday breakfast dish is perfect in its original vegetarian form, offering a delightful and satisfying meal as is, I frequently receive requests for suggestions on how to incorporate meat into vegetarian recipes. For those who prefer a heartier option, there’s absolutely no problem! This casserole is robust enough to welcome some savory additions.

Here are my suggestions for proteins that would make wonderful and delicious additions to this Christmas Croissant Breakfast Casserole:

• **Crumbled Bacon:** Perhaps the most obvious choice, bacon is a universally loved, crowd-pleasing, and easy-to-add meat for nearly any breakfast dish. Its salty, smoky crispness would be a fantastic complement.
• **Diced Ham:** Like bacon, ham offers a wonderful salty flavor that pairs well with the richness of the casserole. Plus, diced ham is often pre-cooked and readily available, making preparation even simpler.
• **Cooked and Crumbled Bulk Sausage:** Whether you prefer hot or mild, crumbled breakfast sausage would integrate beautifully into this croissant egg bake, adding a robust, savory depth.
• **Chorizo:** There are two main types of chorizo – Mexican and Spanish – and both are incredibly delicious, though they require different preparation. If opting for Mexican chorizo (raw), cook and crumble it thoroughly in a skillet, then drain as much fat as possible before adding it to the casserole. If choosing Spanish chorizo (cured and already cooked), simply dice it and give it a quick sauté with the mushrooms to warm it through and brown it slightly before assembling the casserole.
• **Chicken:** While chicken is inherently a bit bland and the flavors in this casserole are somewhat delicate, it’s not my go-to protein addition. However, if you have leftover rotisserie chicken or other well-seasoned, tender cooked chicken, dicing it finely could certainly be a good option for a lighter meat addition.

Creative Vegetarian Additions to Customize Your Casserole

Beyond the core ingredients, there’s plenty of room for creativity to tailor this Christmas Croissant Breakfast Casserole to your specific tastes or to suit your crowd. While I haven’t personally tried all of these, they are fantastic ideas for further enhancing this already delicious dish:

• **Spinach:** Fresh or frozen (thawed and squeezed dry), spinach adds a healthy boost of green and a mild, earthy flavor.
• **Black Beans:** For a heartier, Southwestern-inspired twist, cooked black beans would add a wonderful texture and protein.
• **Diced Potatoes or Sweet Potatoes:** Pre-cooked and diced, potatoes (white or sweet) could add another layer of satisfying carbohydrates and flavor. Consider roasting them lightly beforehand for extra depth.
• **Caramelized Onions:** Slow-cooked caramelized onions would infuse the casserole with a deep, sweet, and savory richness.
• **Jalapeño:** For those who love a bit more heat than poblano provides, finely diced fresh or roasted jalapeño would offer a zesty kick.
• **Green Bell Pepper:** If you want to lean into the “Christmas colors” even more, or simply enjoy the fresh, crisp flavor of green bell pepper, it’s a great addition alongside the red.

I completely understand that people love to customize recipes to fit their particular preferences or what they have on hand. So, feel free to experiment with these suggestions to make this casserole truly your own!

So, there you have it, folks. This Christmas Croissant Breakfast Casserole recipe is a must-try. It strikes the perfect balance of being easy to prepare yet feeling incredibly fancy. Its beautiful, festive appearance, coupled with its comforting flavors, will bring all the wonderful “feelz” to your holiday breakfast, creating cherished memories with those you love.

More Delicious Brunch Recipe Ideas

Looking for more amazing breakfast and brunch recipes? Here are some other delightful ideas to inspire your culinary adventures:

• Pimento Cheese Sausage Balls
• Mexican Chorizo Gravy and Biscuits
• Sausage and Caramelized Onion Quiche
• Roasted Poblano Breakfast Casserole
• Herbed Tomato Tart

Also check out another holiday favorite, the Best Stuffing Ever.

Christmas Croissant Breakfast Casserole

Christmas Croissant Breakfast Casserole is a vegetarian croissant egg bake assembled in advance and baked the next day.

4.75 from 16 votes

Print
Pin
Rate

Course:
Breakfast

Cuisine:
American

Keyword:
croissant breakfast casserole, croissant casserole, croissant egg bake, vegetarian breakfast casserole

Prep Time:

15
minutes

minutes

Cook Time:

45
minutes

minutes

Total Time:

1
hour

hour

Author:

Erica

Servings:
8

Calories:

511
kcal

Equipment

• skillet
• 13×9 bake dish

Ingredients

• 1
  red bell pepper
• 1
  large poblano pepper
• 8
  oz
  mushrooms, chopped
• 2
  Tbs
  unsalted butter
• 3-4
  large croissants, roughly chopped
• ¼
  cup
  green onion
• 2
  Tbs
  flat-leaf parsley
• 1
  cup
  shredded white cheddar cheese
• ½
  cup
  shredded Swiss cheese
• ¼
  cup
  shredded parmesan
• 5
  eggs, lightly beaten
• 1
  cup
  cream
• 1
  cup
  milk
• 1
  tsp
  
  kosher salt
  
• couple pinches fresh cracked pepper

Instructions

• Under the oven broiler, roast the poblano and red bell peppers, turning every 4-5 minutes, until skins are blackened and blistered all over. Move the blackened peppers to a ziploc bag to allow to steam. Once cool enough to handle, remove and discard the skins and seeds. Chop and set aside.
• In a medium skillet, melt the butter. Add the mushrooms and cook, tossing regularly, until nicely browned.
• In a 13×9 baking dish, toss together the poblano pepper, red bell pepper, mushrooms, croissant pieces, green onion, and parsley. Top with the cheeses.
• Combine the eggs, cream, milk, salt, and pepper. Pour over the casserole. Cover with plastic wrap and put in the fridge to set overnight.
• Bake casserole at 350°F for 45 minutes or until center is set. Allow to cool 10 minutes before serving. Yields 8 servings.

Nutrition

Calories:
511
kcal

|

Carbohydrates:
18
g

|

Protein:
24
g

|

Fat:
37
g

|

Saturated Fat:
21
g

|

Polyunsaturated Fat:
2
g

|

Monounsaturated Fat:
8
g

|

Cholesterol:
222
mg

|

Sodium:
905
mg

|

Potassium:
386
mg

|

Fiber:
2
g

|

Sugar:
7
g