Breakfast Strata (Make-Ahead Egg Casserole)

This savory Breakfast Strata is the perfect make-ahead brunch-assemble it the night before and bake it fresh in the morning.

This Breakfast Strata with mushrooms, caramelized onions, goat cheese, and thyme is the perfect make-ahead brunch for holidays or weekends with guests. Assemble it the night before, refrigerate, and simply bake in the morning-no stress, no rushing. It comes out puffed, golden, and wonderfully fragrant.

When it comes out, it will be puffed, golden, and deliciously fragrant. You can also bake this in individual ramekins or mini cast-iron skillets for a fun, different presentation. And of course, you can bake it the same day, too!

Breakfast Casserole Ingredients

• Large eggs: The star of the strata, creating a rich, custardy base that binds everything together while baking into a light, soufflé-like texture.
• Mushrooms: Thinly sliced and sautéed, they bring deep umami and earthy richness that gives the strata a savory, almost “meaty” depth.
• Yellow onion: Slowly caramelized until golden, the onion adds natural sweetness and complexity, balancing the savory elements beautifully.
• Sourdough or French bread: Cubed and toasted, the bread absorbs the custard while maintaining structure, giving the strata its signature contrast of crispy edges and soft, creamy interior.
• Fresh thyme: Adds a subtle, woodsy, aromatic note that complements the mushrooms and enhances the overall warmth of the dish.
• Goat cheese: Creamy and tangy, it melts into pockets throughout the strata, adding brightness and a luxurious texture.
• Grated cheese (Gruyère, Jack, mozzarella, or a blend): Provides melty richness and a golden, slightly crisp top layer. Gruyère adds nuttiness, while mozzarella offers stretch and mildness.
• Whole milk (or half-and-half): Enriches the custard, creating a smooth, velvety consistency without making the dish too heavy.
• Sour cream: Adds extra creaminess with a subtle tang that lifts and balances the richness of the eggs and cheese.
• Bacon (optional): Crispy and smoky, it adds a savory, salty bite that deepens the overall flavor and contrasts with the creamy custard. Brian loves his bacon, so I added bacon crumbles to his half of the strata. Truthfully, I found myself over on his side of the strata more than I want to admit…the smoky bacon crumbles added a lot of flavor! You could also add diced ham or cooked sausage.

How to Make Breakfast Strata

1. Toast the bread cubes. Preheat the oven to 400F. Cut the bread into 3/4-inch cubes and spread them out in an even layer on a baking sheet. Toast in the oven for 10 minutes.

2. Cook the bacon (optional). If adding bacon, spread the strips out onto a lined baking sheet and bake for 20 minutes, or until crisp. When done, blot them and then cut them into small pieces.

3. Sauté the vegetables. Warm a large skillet over medium-high heat and add oil. Add the thinly sliced onions and sauté for 2-3 minutes, then reduce to medium-low heat. Cook until deeply golden and sweet, about 15 minutes, stirring occasionally. In a separate large skillet, heat butter over medium heat and add the sliced mushrooms, cooking until tender, about 10 minutes. To the mushrooms, add fresh thyme and a generous 3-finger pinch of salt and black pepper. Cook off any remaining liquid. Add the caramelized onions to the mushrooms and turn off the heat.

4. Whisk the egg mixture. Add eggs, milk, sour cream, salt, and black pepper to a medium bowl and whisk.

5. Mix the bread, veggies, and eggs. Transfer the toasted bread to a large bowl, then add the mushroom-onion mixture (and bacon crumbles if using). Add shredded cheese and 2/3 of the goat cheese. Mix gently. Pour in the eggs and stir gently. Let sit for 5 minutes.

6. Bake. Give the bowl another stir, then pour into a well-greased 4-quart baking dish. If prepping this for the next morning, you can place the pan in the refrigerator to chill overnight. When ready to bake, cover the dish with foil and place in the oven for 35 minutes. Remove the foil and reduce the temperature to 375F. Continue baking 20-30 minutes until puffed and golden. During the last 20-30 minutes, scatter the remaining goat cheese over the top and let it melt.

7. Garnish and serve. Garnish with a few thyme sprigs, use a sharp knife to cut into squares, and serve warm.

Chef’s Tips

1. Dry out the bread properly. Lightly toasting the cubed bread ensures they absorb the custard without becoming soggy. This is the secret to that perfect, creamy yet structured texture.
2. Don’t rush the caramelized onions. Take your time with the onions. The deeper golden the color, the deeper the flavor. This step adds subtle sweetness that balances the richness of the strata.
3. Cook off the mushroom moisture. Let the mushrooms release and evaporate their liquid fully before combining. This prevents a watery strata and concentrates their flavor.
4. Add greens! Add spinach, arugula, or other greens to the mushroom mixture for a boost in nutrients.
5. Let the strata soak before baking. After mixing, let the strata sit for 5-10 minutes (or overnight) so the bread fully absorbs the custard.
6. If chilled, bring the strata to room temperature before baking. This ensures even cooking and helps the center set properly without over-baking the edges.
7. Bake covered, then uncovered. Covering first keeps the breakfast strata moist and custardy, and uncovering at the end creates that golden, slightly crisp top.
8. Let it rest before slicing. Give the dish 10-15 minutes of resting time so it sets and slices cleanly.

Serving Suggestions

Serve Breakfast Strata with a fruity or citrusy salad, like Pear Salad with Vanilla Fig Dressing, Strawberry and Spinach Salad, or Fennel Orange Salad. We also love it with a side of simple Spring Greens!

Or, serve with other brunch sides and fresh fruit, like breakfast potatoes, vegan bacon, or fruit salad.

Meal Prep & Storage

• Make-ahead: Assemble the dish the night before and refrigerate, covered. Make sure to pull the strata out of the fridge and let it come to room temperature first (for about 40-60 minutes) before placing it in the oven, to help ensure even baking.
• Storage: Transfer leftovers to an airtight container (or cover the cooled pan with plastic wrap) and refrigerate for up to 4 days. Reheat in the oven or toaster oven until warmed through.

On the home front: We are done catering for the year. I always have to let out a huge sigh of relief after the last catering event of the holiday season because now it’s time to relax. We worked our butts off this year, and I’ve been feeling it.

On our first day off, we strapped on our cross-country skis and skied right out the front door. Mother Nature was good to us this year and has blanketed our little world with beautiful, fluffy white snow. Being outside in the snow actually helps us stave off the winter blues, so we try to get outside often.

On our second day off, we went to a movie. It had been so long since I’d been to a movie, I didn’t realize that movie theaters now have commercials before the show, and to my amazement, reclining chairs! What? Where have I been? They were so comfy and cozy, it was impossible not to fall asleep.

More Breakfast Recipes You Might Like

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Breakfast Casserole | 45-second video 

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