Ingredients for Your Christmas Breakfast Casserole

• Bread (stale preferred): This is the base, the sponge for all the glorious eggy goodness. Honestly, day-old bread works wonders here fresh bread just gets too soggy, and nobody wants that. I usually use a sturdy sourdough or challah, but even plain white bread can work in a pinch.
• Cooked Sausage (or bacon): The savory heart of our casserole. I usually cook up a pound of breakfast sausage, crumbled, but crispy bacon bits are a fantastic swap if that’s what you have. Don’t drain all the fat, some of that flavor is gold!
• Large Eggs: The glue that holds this whole amazing dish together. I’ve tried using fewer eggs, and it just doesn’t set right, leaving you with a crumbly mess. Stick with the recipe on this one, trust me.
• Whole Milk: Don’t even think about skim milk, just don’t! Whole milk gives this casserole its luxurious, creamy texture. I tried using a lower-fat milk once, and the richness just wasn’t there. For a dairy-free option, unsweetened almond milk can work, but the texture will be a bit different.
• Sharp Cheddar Cheese: This is where the magic happens! I swear by freshly grated sharp cheddar. Pre-shredded stuff has anti-caking agents that can make it melt weirdly. I always grate a bit extra, because, well, cheese!
• Onion & Bell Pepper (diced): These add a lovely aromatic base and a pop of color and freshness. I usually go for a yellow onion and a red bell pepper for that festive look. I’ve forgotten them once, and the casserole felt a little… flat.
• Dried Mustard & Garlic Powder: These are my secret weapons for a savory kick without being overpowering. The dried mustard adds a subtle tang that just elevates the whole dish. I once thought “more garlic, better!” and, oops, it was a bit much. A little goes a long way.
• Salt & Black Pepper: Essential! Adjust to your taste, of course. I always taste a tiny bit of the egg mixture before adding the bread, just to make sure the seasoning is on point.

Crafting Your Christmas Breakfast Casserole

Prep Your Foundation:

First things first, grab your bread. Tear or cube about 6 cups of it day-old is honestly the best here. It’s a bit firmer and won’t turn to mush when it soaks up all that eggy goodness. Spread it out evenly in a greased 9×13 inch baking dish. I usually just use my hands, it feels more therapeutic that way. Don’t be afraid to make a bit of a mess, that’s part of the fun! Make sure every nook and cranny of that dish is greased, or you’ll have a wrestling match trying to get it out later, like I did that one time. Trust me, butter or cooking spray is your friend.

Sauté the Savory Bits:

Next up, cook your sausage or bacon until it’s beautifully browned. While that’s happening, dice your onion and bell pepper. Once your meat is done, drain some of the fat (but not all! We want flavor!) and then toss in the veggies. Sauté them until they’re soft and fragrant, about 5-7 minutes. I love the smell of the onions caramelizing, it just signals that something delicious is coming. Sometimes I get a little distracted here and almost burn the onions, so keep an eye on them!

Layer the Flavor:

Now, sprinkle half of your cooked sausage and sautéed veggies over the bread cubes in the baking dish. Then, generously scatter half of your freshly grated cheddar cheese over that layer. I always feel like a little kid building a delicious edible fort at this stage. You can add a little extra cheese if you’re feeling it I mean, who’s counting on Christmas morning? This layering ensures every bite of your casserole gets a bit of everything.

Whip Up the Custard:

In a large bowl, whisk together your eggs, whole milk, dried mustard, garlic powder, salt, and pepper. Really get in there with that whisk until everything is well combined and a little frothy. This is the heart of your dish, so make sure it’s seasoned just right. I usually give it a quick taste (just a tiny bit, raw egg is not my jam!) to check the salt. I once forgot the dried mustard, and it just wasn’t the same. It adds a subtle zing!

Pour and Soak:

Carefully pour the egg mixture evenly over the bread, sausage, and cheese in your baking dish. Make sure every piece of bread gets a good soak. This is where the magic really starts to happen! Then, scatter the remaining sausage, veggies, and cheese over the top. Gently press down on the bread with a spatula to ensure it’s fully submerged. I sometimes get a bit impatient here, but letting it soak is crucial for that soft, custardy texture. Cover the dish tightly with plastic wrap.

Chill and Bake Your Christmas Breakfast Casserole:

Pop your covered Christmas Breakfast Casserole into the fridge for at least 4 hours, or even better, overnight! This soaking time is a game-changer for flavor and texture. When you’re ready to bake, preheat your oven to 350°F (175°C). Uncover the casserole and bake for 45-55 minutes, or until it’s golden brown and puffed up, and a knife inserted into the center comes out clean. It should smell incredible, a mix of savory and warm spices. Let it rest for 10 minutes before serving. Honestly, that rest time is hard, but it helps everything set beautifully!

Christmas Breakfast Casserole Storage Tips

Okay, let’s talk leftovers for this casserole. If you manage to have any, that is! I’ve had my share of storage mishaps, like trying to freeze a saucy casserole without proper wrapping, and it just ended up with freezer burn. For this beauty, once it’s cooled completely, you can cover it tightly with plastic wrap or pop it into an airtight container. It’ll keep beautifully in the fridge for up to 3-4 days. Reheating is easy, I usually just pop a slice in the microwave for a minute or two, or if I’m feeling fancy, a quick warm-up in the oven at 300°F (150°C) helps crisp up the edges again. Just don’t overheat it in the microwave, or the eggs can get a bit rubbery I’ve done that, and it’s not fun.

Casserole Ingredient Substitutions

Through my kitchen experiments, I’ve tried a few swaps for this dish. If you’re out of sharp cheddar, a Monterey Jack or even a mild provolone works, though the flavor will be a bit milder. I once used a smoked gouda, and it was… interesting, but maybe not for everyone! For the sausage, diced ham or even cooked ground turkey can step in. I tried a vegetarian version with sautéed mushrooms and spinach, and it worked, kinda. It lacked that hearty meatiness, but it was still a decent breakfast. If you don’t have whole milk, a mix of half-and-half and a splash of water can mimic the richness, but honestly, whole milk is the star here. Don’t be afraid to experiment a little, but know that some swaps will change the overall character of your Christmas Breakfast Casserole.

Christmas Breakfast Casserole Serving Suggestions

How do I serve this magnificent dish? Oh, let me count the ways! For a holiday morning, I love to pair it with a simple fruit salad something bright and fresh to cut through the richness. A pitcher of mimosas or a strong cup of coffee is a must, of course! Sometimes, I’ll add a side of crispy hash browns, but honestly, the casserole is so hearty it doesn’t even need it. For a casual brunch, a dollop of sour cream or a sprinkle of fresh chives on top can elevate it. This dish and a good holiday movie? Yes, please! It just makes those lazy, festive mornings feel even more special.

The Story Behind This Breakfast Casserole

While the concept of a breakfast casserole isn’t tied to one specific culture, its heart is deeply rooted in communal, make-ahead meals, especially popular in American holiday traditions. For me, this Christmas Breakfast Casserole reminds me of my grandmother’s kitchen, where she always had something delicious baking for Christmas morning, usually a sweet roll. This savory version is my spin on that comforting memory, a way to gather everyone around the table without the cook being stuck in the kitchen. It’s a dish born from the desire to create warmth, ease, and shared joy during the busiest time of the year. It’s about family, tradition, and a little less stress.

Frequently Asked Questions

→ Can I make this Christmas Breakfast Casserole vegetarian?

Absolutely! I’ve swapped the sausage for sautéed mushrooms, spinach, and maybe some sun-dried tomatoes before. It worked pretty well, just a different flavor profile, but still hearty and delicious for a meatless breakfast.

→ What’s the best bread to use for this Christmas Breakfast Casserole?

Honestly, a sturdy, day-old bread like sourdough, challah, or even a good French loaf is ideal. Fresh sandwich bread can get too soggy, which I learned the hard way in an “oops” moment. The sturdier bread holds its shape better.

→ How do I know if my Christmas Breakfast Casserole is fully cooked?

It should be golden brown and puffed up, and a knife inserted into the center should come out clean. I always check the middle because sometimes the edges look done, but the center needs a little more time. Don’t pull it too early!

→ Can I freeze leftover Christmas Breakfast Casserole?

Yes, you can! Just make sure it’s completely cooled, then wrap individual portions tightly in plastic wrap and foil. It’ll keep for about a month. Reheat gently in the oven. I tried microwaving from frozen once, and it got a bit rubbery, so oven is better.

→ Can I add other vegetables to this Christmas Breakfast Casserole?

Oh, for sure! I’ve thrown in diced zucchini, chopped spinach, or even some roasted sweet potato cubes. Just make sure to pre-cook any harder veggies so they’re tender. It’s fun to experiment with what you have on hand!