Introduction

This Easter Breakfast Casserole from Martha Stewart is a warm, comforting dish that combines savory sausage, sautéed vegetables, and gooey cheese baked into a creamy custard. It’s perfect for holiday mornings or any special brunch gathering, offering both heartiness and rich flavors that everyone will love.

A white ceramic rectangular dish holds a creamy baked casserole with a golden-brown top layer that looks bubbly and slightly crispy. The top layer has uneven puffed sections with toasted spots in light and dark amber tones. Inside, a creamy white mixture is visible, with yellow corn kernels and some small brown pieces. A few small green herb sprigs sit on top near the center. The dish rests on a soft white cloth over a white marbled surface. In the background, there are blurred white flowers, brown eggs, and white kitchen items. photo taken with an iphone --ar 4:5 --v 7

Ingredients

2 tablespoons olive oil

1 pound bulk pork sausage

8 ounces cremini mushrooms

1 medium onion

4 cups fresh spinach

8 slices sturdy white bread

1 cup Gruyère cheese

Salt, to taste

Black pepper, to taste

8 large eggs

2 cups whole milk

1 cup heavy cream

2 tablespoons Dijon mustard

1 teaspoon fresh nutmeg

Instructions

Step 1: Heat olive oil in a skillet over medium-high heat. Brown the sausage until fully cooked, then remove from the pan.

Step 2: In the same skillet, sauté the chopped onion and mushrooms until soft. Add the spinach and cook until wilted and bright green.

Step 3: Grease a 9×13-inch baking dish with olive oil. Layer half of the cubed bread on the bottom, then half of the cooked sausage and sautéed vegetables. Sprinkle a generous handful of Gruyère cheese on top. Repeat this layering once more.

Step 4: In a large bowl, whisk together the eggs, whole milk, heavy cream, Dijon mustard, nutmeg, salt, and pepper until smooth and fully combined.

Step 5: Pour the egg mixture evenly over the layered ingredients in the baking dish. Press down gently to help the custard soak in. Cover with plastic wrap and refrigerate for at least 4 hours, preferably overnight.

Step 6: Before baking, let the casserole sit at room temperature for 30 minutes. Preheat the oven to 350°F (175°C) and bake uncovered for 50-60 minutes until puffed and golden brown, with the center set. Let it rest for 10 minutes before serving.

Tips & Variations

Substitute turkey or chicken sausage for a lighter option without sacrificing flavor.

Use Swiss or cheddar cheese if Gruyère is unavailable for a similar creamy texture.

Try kale or Swiss chard instead of spinach for more texture and earthiness.

For a dairy-free version, replace whole milk and heavy cream with full-fat coconut milk.

Make the casserole the night before to deepen the flavors and reduce prep time on the morning of serving.

FAQs

Can I freeze this casserole?

Yes, the casserole freezes well. Wrap it tightly after baking or freeze the assembled dish before baking. Thaw overnight in the refrigerator before reheating or baking.

Can I use a different type of bread?

Yes, sturdy white bread is recommended, but you can use sourdough or whole wheat bread if preferred. Avoid very soft or fresh bread as it may become too mushy.