Buttery Croissant Breakfast Casserole
A restaurant-level brunch dish with buttery croissants, crisp slab bacon, and a nutty Gruyere custard infused with brown butter and fresh sage. Perfect for a cozy holiday morning.
Equipment
- 9x13 Baking Dish
- Small pan
- Skillet
- large bowl
- Whisk
Ingredients
- 8 large croissants ripped into 2-3-inch pieces
- 8 oz slab bacon sliced into batons about ¼-inch thick
- 1 cup Gruyere cheese shredded
- 1/2 cup white Cheddar cheese shredded
- 8 large eggs
- 2 cups whole milk
- 1 cup heavy cream
- 2 Tbsp finely chopped sage
- 2 tsp Dijon mustard
- 1 tsp Kosher salt
- 1/4 tsp freshly ground black pepper
Instructions
Brown butter infusion and oven prep
- Preheat your oven to 350F and coat a 9x13 baking dish with nonstick cooking spray to ensure the custard releases cleanly from the corners.
- Brown 2 to 3 tablespoons of butter in a small pan until it becomes fragrant and the milk solids turn amber. Whisk the warm brown butter into the whole milk and heavy cream, adding a pinch of freshly grated nutmeg if desired.
Crisp the bacon and build the base
- Place a skillet over medium heat and add the slab bacon batons. Stir frequently for 4 to 5 minutes until the fat renders and the bacon is bronzed and crisp.
- Using a slotted spoon, remove the bacon from the skillet and spread it evenly across the bottom of the prepared baking dish.
Layer, pour, and finish with a golden bake
- Mix the Gruyere and white Cheddar together. Scatter half of the cheese over the bacon, then tuck the croissant pieces on top loosely, ensuring some tips point upward for extra crunch.
- In a large bowl, whisk the eggs until fully combined. Mix in the infused milk and cream mixture, sage, Dijon mustard, salt, and pepper. Slowly pour the custard over the croissants and top with the remaining cheese.
- Bake for 40 to 45 minutes until the top is golden brown and the cheese is crisp. If the croissants brown too quickly, cover loosely with foil after 30 minutes.
- Remove from the oven and let the casserole cool for 5 to 10 minutes to allow the custard center to set properly before slicing.
Notes
Safety Tip: Use a food thermometer to ensure the center of the casserole reaches an internal temperature of 160°F (71°C) for a safe and tender set.
Storage Tip: Refrigerate leftovers in a covered container for 3 to 4 days. Reheat in a 350F oven to maintain the croissant texture, as microwaves may make them rubbery.
Variation Tip: For a sweet-savory twist, serve with a bright citrus fruit salad or berries to cut through the richness of the butter and cheese.
Nutrition information is estimated based on common ingredients and serving sizes and may vary.