Description

This Easy Breakfast Casserole is a hearty and flavorful morning dish perfect for feeding a crowd or enjoying leftovers throughout the week. Layers of crusty bread, savory sausage, sautéed vegetables, and a cheesy egg mixture bake together into a golden, satisfying casserole. With its simple preparation and make-ahead option, this breakfast casserole provides a comforting and customizable meal to start your day right.

Ingredients

Base

4 cups (175g or 6 oz) cubes of crusty bread
1 teaspoon olive oil

Sausage and Vegetables

1 pound ground sausage, casings removed
1 teaspoon dried rosemary or Italian seasoning (optional)
3/4 cup (100g) chopped yellow onion (1/2 of a large onion)
2 garlic cloves, minced
2 cups (275g or 9-10 oz) chopped bell peppers
1 cup (100g or 3 oz) sliced mushrooms
1 cup roughly chopped fresh spinach

Egg Mixture

12 large eggs
1/4 teaspoon salt
1/8 teaspoon freshly ground black pepper
2/3 cup (160ml) milk or half-and-half
1 cup (100g or 3.5 oz) shredded cheddar cheese

Optional Garnish

Green onion and/or chopped parsley

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Instructions

Prepare the dish: Grease a 9×13-inch or any 3–4-quart oven-safe dish. Arrange the cubes of crusty bread evenly in the bottom of the pan to form the base layer.
Cook sausage and vegetables: Heat the olive oil in a large skillet over medium heat. Add the ground sausage and sprinkle with dried rosemary or Italian seasoning if using. Break the sausage into bite-sized pieces with a wooden spoon or rubber spatula. After the sausage starts to brown, add the chopped onion, minced garlic, bell peppers, mushrooms, and spinach. Cook for about 5–6 minutes until the vegetables soften and the sausage is mostly cooked through.
Assemble the layers: Remove the sausage and vegetable mixture from heat and spread it evenly over the layer of bread cubes in the casserole dish.
Mix eggs and pour: In a large bowl, whisk together the eggs, salt, black pepper, milk or half-and-half, and shredded cheddar cheese. Pour this egg mixture evenly over the sausage and vegetables in the dish. Sprinkle an additional pinch of salt and pepper on top for seasoning.
Refrigerate to set: Cover the casserole tightly with plastic wrap or aluminum foil and refrigerate for at least 30 minutes, or up to 24 hours. This allows the bread to soak up the egg mixture thoroughly. Before baking, let the casserole sit at room temperature for 10–15 minutes while you preheat the oven.
Bake the casserole: Preheat your oven to 375°F (191°C). Bake the uncovered casserole for 40 to 45 minutes, until the top is golden brown, edges are crisp, and a toothpick inserted into the center comes out clean.
Cool and serve: Allow the casserole to cool for 10 minutes after baking. Then slice into portions and serve warm. Garnish with green onion or chopped parsley if desired.
Store leftovers: Leftover casserole keeps well refrigerated for up to 5 days. Reheat portions in the microwave to enjoy later.

Notes

Use crusty bread like a baguette or artisan loaf for better texture; avoid very soft bread.
You can substitute ground breakfast sausage with turkey sausage or vegetarian sausage if preferred.
Feel free to customize the vegetables—add zucchini, tomatoes, or other favorite veggies.
Half-and-half makes the casserole richer, but whole milk works well too.
Cover and refrigerate the casserole overnight for easy prep ahead breakfast or brunch.
To make it gluten-free, use gluten-free bread and ensure sausage and seasonings are gluten-free.

Prep Time: 30 minutes
Cook Time: 45 minutes
Category: Breakfast
Method: Baking
Cuisine: American