Savory Breakfast Strata With Bread, Eggs, Cheese, and Veggies

Quick Recipe Version (TL;DR)

• Yield: 8 servings (9×13-inch strata)
• Prep Time: 25 minutes
• Cook Time: 50 minutes
• Total Time: 1 hour 45 minutes (includes 30-minute soak)

Quick Ingredients

• 12 oz (340 g) sturdy bread (sourdough or French), cut into 1-inch cubes (about 8 cups)
• 2 tbsp (28 g) unsalted butter, divided
• 8 oz (225 g) cremini mushrooms, sliced
• 1 medium yellow onion, thinly sliced
• 3 cups (90 g) baby spinach
• 10 large eggs
• 2 cups (480 ml) whole milk
• 1/2 cup (120 ml) heavy cream
• 1 tbsp Dijon mustard
• 1 1/4 tsp kosher salt
• 1/2 tsp black pepper
• 1 tsp garlic powder
• 1 tsp dried thyme
• 2 1/2 cups (250 g) shredded sharp cheddar, divided
• 1 cup (100 g) shredded Gruyère, divided
• Optional: 6 slices bacon, cooked and chopped (about 3/4 cup)

Do This

• 1. Butter a 9×13-inch baking dish; add bread cubes.
• 2. Sauté onion and mushrooms in butter; wilt spinach; cool 5 minutes.
• 3. Whisk eggs, milk, cream, Dijon, salt, pepper, garlic powder, and thyme.
• 4. Layer bread, vegetables (and bacon if using), and most of the cheese.
• 5. Pour custard over; press gently; soak 30 minutes (or refrigerate overnight).
• 6. Bake at 350°F (177°C) for 45–55 minutes until puffed and golden (center 160°F/71°C).
• 7. Rest 10–15 minutes; slice and serve warm.

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Why You’ll Love This Recipe

• Make-ahead friendly: Assemble the night before, then bake in the morning.
• Big payoff, low stress: Simple ingredients transform into a custardy, golden brunch bake.
• Flexible: Use your favorite cheese, vegetables, or breakfast meat.
• Great for a crowd: One 9×13 pan serves 8 with no short-order cooking.

Grocery List

• Produce: 1 medium yellow onion, 8 oz (225 g) cremini mushrooms, 3 cups (90 g) baby spinach
• Dairy: unsalted butter, 10 large eggs, whole milk, heavy cream, sharp cheddar, Gruyère
• Pantry: sturdy bread (sourdough or French), Dijon mustard, kosher salt, black pepper, garlic powder, dried thyme
• Optional: bacon (or another cooked breakfast meat)

Full Ingredients

Base & Pan

• 12 oz (340 g) sturdy bread (sourdough or French), cut into 1-inch cubes (about 8 cups)
• 2 tbsp (28 g) unsalted butter, divided (plus a bit more for the dish if needed)

Vegetables (Savory Filling)

• 1 medium yellow onion, thinly sliced
• 8 oz (225 g) cremini mushrooms, sliced
• 3 cups (90 g) baby spinach

Optional Meat

• Optional: 6 slices bacon, cooked until crisp and chopped (about 3/4 cup)

Custard

• 10 large eggs
• 2 cups (480 ml) whole milk
• 1/2 cup (120 ml) heavy cream
• 1 tbsp Dijon mustard
• 1 1/4 tsp kosher salt
• 1/2 tsp freshly ground black pepper
• 1 tsp garlic powder
• 1 tsp dried thyme

Cheese

• 2 1/2 cups (250 g) shredded sharp cheddar, divided
• 1 cup (100 g) shredded Gruyère, divided

Step-by-Step Instructions

Step 1: Prep the pan and bread

Butter a 9×13-inch baking dish. Add the bread cubes and spread them into an even layer. If your bread is very fresh and soft, let the cubes sit out while you prep the filling (10–15 minutes) so they dry slightly and soak up custard better.

Step 2: Sauté the onion and mushrooms

In a large skillet over medium heat, melt 1 tbsp of the butter. Add the sliced onion and cook, stirring occasionally, for 6–8 minutes until softened and lightly golden.

Add the mushrooms and cook for 6–8 minutes, stirring occasionally, until they release their moisture and the pan looks mostly dry. This keeps your strata from getting watery.

Step 3: Wilt the spinach and cool the filling

Add the remaining 1 tbsp butter to the skillet, then add the spinach. Toss for 30–60 seconds, just until wilted. Remove from the heat and let the mixture cool for 5 minutes (so it doesn’t start cooking the eggs when combined).

Step 4: Whisk the custard

In a large bowl, whisk the eggs until no streaks remain. Whisk in the milk, heavy cream, Dijon mustard, salt, pepper, garlic powder, and thyme. The Dijon adds a gentle tang and helps the custard taste well-seasoned throughout.

Step 5: Layer bread, filling, and cheese

Sprinkle about half of the sautéed vegetables over the bread. If using bacon, scatter it evenly over the vegetables.

Add 2 cups (200 g) of the cheddar and 3/4 cup (75 g) of the Gruyère, reserving the rest for the top. Add the remaining vegetables over the cheese.

Step 6: Add custard and soak

Slowly pour the custard mixture evenly over the strata. Use a spatula to gently press the bread down so the top cubes start absorbing liquid.

Let the strata stand at room temperature for 30 minutes to soak. For a true make-ahead breakfast, cover tightly and refrigerate for 8–12 hours. If refrigerated, let it sit at room temperature for 20 minutes before baking while the oven heats.

Step 7: Bake until custardy and golden

Preheat the oven to 350°F (177°C). Sprinkle the remaining 1/2 cup (50 g) cheddar and 1/4 cup (25 g) Gruyère over the top.

Bake uncovered for 45–55 minutes, until puffed, deeply golden on top, and the center is set. For best accuracy, the center should reach 160°F (71°C) on an instant-read thermometer.

Let rest for 10–15 minutes before slicing. This settling time helps the custard finish setting so servings hold together neatly.

Pro Tips

• Use sturdy bread: Sourdough, French bread, or ciabatta holds structure. Very soft sandwich bread can turn gummy.
• Cook off moisture: Don’t rush the mushrooms. A drier filling means a richer, custardier strata.
• Overnight is best: An 8–12 hour soak gives the most even, custardy texture (especially with larger bread cubes).
• Check the center: If the top browns too fast, loosely tent with foil for the last 10–15 minutes.
• Rest before cutting: 10–15 minutes makes cleaner slices and better texture.

Variations

• Ham and broccoli: Replace bacon with 1 1/2 cups (225 g) diced cooked ham and swap spinach for 2 cups (180 g) small steamed broccoli florets (well-drained).
• Southwest: Use pepper jack instead of Gruyère, add 1 cup (150 g) diced bell pepper, and swap thyme for 1 1/2 tsp chili powder. Serve with salsa.
• Vegetarian “allium lover”: Skip bacon, double the mushrooms to 16 oz (450 g), and add 2 thinly sliced scallions stirred into the custard.

Storage & Make-Ahead

Make-ahead: Assemble through adding the custard, cover tightly, and refrigerate for 8–12 hours. Bake as directed (you may need an extra 5–10 minutes if going into the oven cold).

Refrigerate leftovers: Cool completely, cover, and refrigerate for up to 4 days.

Reheat: Warm individual portions in the microwave for 60–90 seconds, or reheat in a 350°F (177°C) oven until hot, about 10–15 minutes. If reheating a larger section, cover with foil to prevent over-browning.

Freeze: Wrap individual slices tightly and freeze for up to 2 months. Thaw overnight in the fridge and reheat as above.

Nutrition (per serving)

Approximate (1/8 of recipe, with bacon): 460 calories, 26 g protein, 29 g fat, 23 g carbs, 2 g fiber, 820 mg sodium.