This crowd-pleasing Everything Bagel Breakfast Casserole is about to make your special-occasion breakfast or brunch a whole lot more delicious! It is best when assembled the night before allowing the bagels to soak up the egg custard. Just mix it all up and put it in the fridge overnight, then bake away in the morning.
Prep Time20 minutesmins
Cook Time55 minutesmins
Total Time1 hourhr15 minutesmins
Servings: 8- 10
Ingredients
1pounduncooked breakfast sausage(omit to make vegetarian)
1tablespoonbutterplus extra for greasing pan
1large onionthinly sliced
5ouncesbaby spinach
3large day-old everything bagels (or 4 small)cut into 2-inch chunks
1small red bell pepperfinely chopped
3scallionsfinely sliced
1 1/2cupsgrated Gruyère, or sharp cheddar, or a mixdivided
2teaspoonskosher salt and freshly ground black pepperdivided
8large eggs
2cupswhole milk, or half and half, or a mix
2tablespoonsDijon mustard
4ouncescold cream cheesecut into small cubes
Instructions
Grease a 9x13-inch baking dish, or equivalent.
Heat a large skillet over medium heat. Add the sausage and cook until golden-brown and cooked through, about 8 to 10 minutes. Transfer to a paper towel-lined plate and don't wipe the skillet.
Add the butter to the skillet and once melted add the onion. Cook until slightly softened and caramelized, about 5 minutes. Add the spinach and sauté until wilted, about 2 minutes. Transfer onion-spinach mixture to a large bowl. Cut the sausage into 1-inch pieces and add to the bowl along with the bagel chunks, half of the gruyere cheese, red peppers, scallions, salt and pepper. Using your hands or a spatula, toss everything together until well combined. Transfer the bagel mixture to prepared baking dish and arrange everything in a single layer.
In a separate mixing bowl, whisk together: eggs, milk, dijon mustard, salt, and pepper. Pour the egg mixture evenly over top. Dot with the pieces of cream cheese.
Cover tightly and refrigerate for 2 to 6 hours, but preferably overnight. Let the chilled casserole sit at room temperature for 15 to 20 minutes before baking.
When ready to bake, sprinkle with remaining gruyere cheese and cover with foil. Bake for 40 minutes. Remove foil and bake until top is golden brown and egg mixture is set, about 15 to 20 minutes longer. Let sit for 5 to 10 minutes before serving.
Make Ahead: Assemble casserole completely, but don't top with remaining cheese. Cover tightly and store in the refrigerator overnight. When ready to bake, top with remaining cheese and bake as instructed.
Store: Everything bagel breakfast casserole leftovers are delicious for days. Store any leftovers in an airtight container in the refrigerator for up to 3 days. Reheat in a preheated oven until warmed through.
Freeze: Assemble and bake the casserole. Cool completely and cover tightly with two layers of foil. When ready to use, thaw in the refrigerator overnight then place in a 350ºF preheated oven and bake, covered, until warmed through.