Overnight Bacon and Egg Strata Recipe

Inside: Why slightly stale bread is essential for a good strata, and why an overnight soak makes all the difference.

This breakfast strata with bacon is a dependable recipe you’ll return to again and again. It combines crisp bacon, melted cheese, sautéed mushrooms and sweet caramelized onions in a savory bread-and-egg custard. The result is a comforting, crowd-friendly egg strata that’s ideal for holiday mornings, weekend brunches, or any time you want a simple make-ahead breakfast casserole.

A strata is a layered savory bread casserole: cubes of bread are mixed with vegetables, meat and cheese, then drenched in a seasoned egg-and-milk custard and baked until the top is golden and the center is tender and custardy. This method is very forgiving and highly adaptable — swap in different cheeses, vegetables or proteins to suit your pantry. The version below focuses on smoky bacon, earthy mushrooms and deeply flavored caramelized onions for a balanced, satisfying dish.

Why this recipe works

Stale bread holds the custard. Slightly dry bread soaks up the egg mixture without falling apart, yielding a soft interior and a crisp, golden top. Using fresh, soft bread will make the strata sloppy and unstable.
Make-ahead convenience. Assemble the night before and refrigerate so the custard fully penetrates the bread. Baking in the morning keeps stress low for holidays and busy brunches.
Caramelized onions add depth. Slowly cooked onions provide a subtle sweetness that pairs beautifully with smoky bacon and savory mushrooms.
Great texture contrast. The ratio of egg to bread creates a creamy, custardy middle and a firm, browned surface.
Flexible and scalable. This casserole scales up easily and welcomes substitutions like different cheeses, greens or roasted vegetables.

Ingredients

1/2 pound bacon, chopped — thick-cut works well, cooked until crisp.
16 ounces mushrooms (baby bella or button), sliced and browned.
1 cup caramelized onions (see notes if you need a quick version).
5 cups stale Italian or sourdough bread, crusts removed and cut into 1″ cubes. (If fresh, cube and leave uncovered overnight.)
2 cups shredded mozzarella — or substitute cheddar, gruyere, gouda, pepper jack, Swiss, or a blend.
1/4 cup chopped parsley, optional for freshness and color.
5 large eggs.
1 1/4 cups milk (whole milk gives the richest custard).
1/2 teaspoon kosher salt (adjust if using fine table salt).
1/4 teaspoon white pepper (or black pepper).
1/8 teaspoon cayenne, a pinch to brighten the flavors.
1/4 teaspoon dry mustard, for a subtle tang that boosts the cheese flavor.
1/2 teaspoon dried thyme.
1/2 teaspoon onion powder, to reinforce the onion flavor.

Step-by-step instructions

Caramelize the onions ahead of time. You can make them several days in advance and refrigerate, or freeze portions for later use.
Remove crusts and cut the bread into 1″ cubes. If the bread is fresh, spread the cubes on a baking sheet and leave them uncovered for several hours or overnight to dry out.
Cut the bacon into bite-sized pieces and cook in a large skillet over medium-high heat until crisp. Drain on paper towels.
Reserve about 1 tablespoon of bacon fat, then add the mushrooms and a pinch of salt to the skillet. Sauté over medium-high heat until the mushrooms release their moisture and begin to brown; if needed, cook in batches so they sear rather than steam.
In a large bowl, combine the stale bread cubes with the crisp bacon, browned mushrooms and caramelized onions. Break up any onion clumps with your fingers and toss to mix evenly.
Add the shredded cheese and parsley, toss again, and transfer the mixture to a buttered or sprayed 2-quart casserole dish, spreading it evenly.
Whisk the eggs with the milk, salt, white pepper, cayenne, dry mustard, thyme and onion powder in a medium bowl. Pour the custard evenly over the bread mixture.
Cover the casserole and refrigerate for several hours or overnight to allow the bread to absorb the custard. Remove it from the fridge about 30 minutes before baking to take the chill off.
Preheat the oven to 375°F (190°C). Bake the strata in the center of the oven for 50–60 minutes, or until the top is golden and the center is set (test with a knife; it should come out mostly clean).
Let the strata rest for 10 minutes before serving to make slicing easier and to allow the custard to settle.

Combine the cubed bread with bacon, mushrooms, caramelized onions cheese and parsley

Pro tips

Cut the bacon into bite-size pieces before frying for even distribution through the strata.
Make sure mushrooms are well-browned and most of their liquid has cooked off to prevent a soggy casserole.
Stale, sturdy bread (sourdough or Italian) is essential. If you forget to buy stale bread, cube fresh bread and leave it uncovered overnight.

bake the onion and bacon strata until golden and cooked through.

Swaps and variations

Use sautéed or grilled onions if you don’t have time to caramelize them; avoid raw onions.
Swap mozzarella for cheddar, gruyere, gouda, pepper jack, Swiss or a blend for different flavor profiles.
Scatter grated Parmesan on top before baking for a savory crust.
Substitute or add vegetables like spinach, kale, bell peppers or summer squash — sauté and dry them first to avoid excess moisture.

Baked bacon breakfast strata with coffee and fresh berries on the side.

FAQs

What’s the difference between a frittata and a strata?

A frittata is an egg-forward skillet dish finished in the oven, typically made and served the same day. A strata is a bread-based egg casserole that benefits from resting so the bread can absorb the custard; it’s often assembled ahead of time and baked later.

How long should the strata soak?

Soak for at least 2 hours so the bread absorbs the custard evenly. Overnight gives the best texture and flavor.

Make ahead, storage and reheating

Make the strata the night before and refrigerate covered. Bake the next morning for fresh results.
Leftovers keep in the refrigerator for 3–4 days. Reheat in a low oven (300°F) covered for 15 minutes, then uncover for 5–8 minutes to crisp the top. The microwave will reheat but won’t preserve the crust.
To freeze, bake first, cool completely, wrap tightly and freeze up to one month. Defrost before reheating at 300°F until heated through.

A serving of bacon strata on a plate with coffee in the background.

Serve this bacon breakfast casserole with a simple fruit salad, coffee and pastries for a complete brunch spread. It’s an easy, make-ahead centerpiece that feeds a crowd and keeps the morning relaxed and delicious.