Description
A rich, savory, make-ahead casserole filled with sausage, cheese, and sourdough—perfect for effortless Christmas mornings. This Martha Stewart–style Christmas Breakfast Casserole delivers cozy flavor with minimal prep.
Ingredients
1 lb turkey breakfast sausage
1 large yellow onion, chopped
1 loaf (1 lb) sourdough bread, cut into 1-inch cubes
2 cups shredded Gruyère cheese
1/2 cup grated Parmesan cheese
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 until browned, then drain the grease.
In a large bowl, combine bread cubes, cooked sausage, onions, and cheeses. Transfer to a greased 9×13-inch baking dish.
In the same bowl, whisk eggs, milk, cream, mustard, salt, pepper, and nutmeg.
Pour the custard evenly over the bread mixture. Cover and refrigerate for at least 8 hours or overnight.
Preheat oven to 350°F (175°C). Let the casserole sit at room temperature for 30 minutes.
Bake uncovered for 50–60 minutes or until golden, puffed, and set in the center.
Cool for 10 minutes before serving.
Notes
Day-old sourdough works best because it absorbs the custard beautifully.
You can swap Gruyère for cheddar or Swiss if preferred.
For a milder flavor, use mild pork sausage or turkey sausage.
This casserole freezes well baked or unbaked for up to 2 months.
- Prep Time: 20 minutes
- Cook Time: 60 minutes
- Category: Breakfast, Brunch, Holiday Recipes
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 slice (approx. 1/10 of casserole)
- Calories: Approximately 435 kcal
- Sugar: 4 g
- Sodium: 820 mg
- Fat: 30 g
- Saturated Fat: 15 g
- Unsaturated Fat: 11 g
- Trans Fat: 0.4 g
- Carbohydrates: 23 g
- Fiber: 1 g
- Protein: 22 g
- Cholesterol: 200 mg