Martha Stewart Christmas Breakfast Casserole Recipe
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4.5 from 54 reviews
A rich and savory Christmas breakfast casserole featuring pork sausage, sourdough bread, Gruyère and Parmesan cheeses baked in a creamy egg custard. Perfect for holiday mornings and make-ahead brunches.
Total Time:9 hours 20 minutes
Yield:8 servings
Ingredients
Casserole
1 lb pork breakfast sausage
1 large yellow onion, chopped
1 (1-pound) loaf sourdough bread, cut into 1-inch cubes
2 cups shredded Gruyère cheese
1/2 cup grated Parmesan cheese
Egg Custard
8 large eggs
2 cups whole milk
1 cup heavy cream
1 tbsp Dijon mustard
1 tsp salt
1/2 tsp black pepper
1/4 tsp ground nutmeg
Instructions
Cook sausage and onion. In a skillet over medium heat, cook the pork breakfast sausage and chopped yellow onion until browned and cooked through. Drain any excess grease and set aside.
Combine bread and cheese. In a large bowl, mix the 1-inch cubed sourdough bread with the cooked sausage and onion mixture, shredded Gruyère cheese, and grated Parmesan cheese until well combined.
Prepare baking dish. Transfer the bread and sausage mixture to a greased 9×13-inch baking dish, spreading it evenly.
Make the egg custard. In the same large bowl, whisk together the eggs, whole milk, heavy cream, Dijon mustard, salt, black pepper, and ground nutmeg until smooth.
Combine custard with casserole. Pour the egg custard evenly over the bread mixture in the baking dish. Cover the dish with plastic wrap or foil and refrigerate for at least 8 hours or overnight to allow the casserole to soak.
Preheat and rest. When ready to bake, preheat the oven to 350°F (175°C) and remove the casserole from the refrigerator, letting it sit at room temperature for 30 minutes.
Bake until golden. Bake the casserole uncovered for 60 minutes, or until the top is golden brown and the custard is fully set. A knife inserted in the center should come out clean.
Rest before serving. Let the casserole rest for 10 minutes before slicing and serving to allow it to firm up.
Notes
For a make-ahead option, prepare the casserole the night before and bake fresh in the morning.
You can substitute the pork sausage with turkey sausage for a leaner option.
Gruyère can be replaced with Swiss or mozzarella cheese if unavailable.
Ensure the casserole rests before baking to allow the bread to absorb the custard fully, which improves texture.
Use a sharp knife to cut the casserole into neat squares.
