Bacon, Mushroom & Spinach Breakfast Casserole Recipe

This Bacon, Mushroom and Spinach Breakfast Casserole is hearty and simple to assemble. It’s ideal for a relaxed weekend breakfast, a special brunch with friends, or a cozy breakfast-for-dinner night.

Why I Love This Bacon and Vegetable Breakfast Casserole

I’ve been focusing on easy meals that deliver big flavor with minimal effort, and this Bacon, Mushroom, and Spinach Breakfast Casserole fits the bill. It combines crispy bacon and sautéed mushrooms with tender eggs, producing a satisfying, savory casserole that’s both comforting and impressive.

The casserole pairs salty bacon with earthy mushrooms and bright spinach for color and nutrients without overwhelming the dish. It’s rich enough to please adults and mild enough that kids tend to enjoy it too, making it a reliable family favorite.

This dish is especially good for holiday mornings because it’s straightforward to prep and fills the house with an inviting aroma. It also makes a great option for dinner—“Brinner”—when you want something hearty and different without extra effort.

Ingredients

The base of this casserole is eggs and milk for a light, fluffy custard. The fillings add texture and flavor—bacon, mushrooms, and spinach, plus hash browns and cheese for body and richness.

• Thick-cut bacon
• Mushrooms
• Onion
• Garlic
• Frozen hash browns
• Spinach
• Swiss cheese and grated Parmesan

Step By Step Instructions

Step 1: Preheat and Prep

Preheat the oven to 350°F (175°C). Lightly grease a 1 1/2‑quart baking dish and set aside.

Step 2: Cook Bacon and Mushroom Mixture

In a large skillet, cook the bacon over medium to medium-low heat until crispy. Transfer the bacon to paper towels to drain, leaving about 2 tablespoons of bacon grease in the skillet. Add the sliced mushrooms and chopped onion and cook 5–7 minutes until lightly browned. Add the minced garlic and cook another 1–2 minutes. Remove from heat and crumble the bacon.

Step 3: Combine Mixture with Eggs and Milk

In a large bowl, whisk together the eggs and milk. Stir in the crumbled bacon, frozen hash browns, roughly chopped spinach, grated Swiss, Parmesan, and the mushroom-onion mixture until evenly combined.

Step 4: Bake

Pour the mixture into the prepared baking dish and bake for about 45 minutes, or until the center is set and no longer runny. Let it rest a few minutes before slicing.

Variations and Serving Suggestions

• Swap or add vegetables: broccoli, bell peppers, or zucchini work well.
• Swap the bacon for breakfast sausage or a plant-based sausage for a different protein option.
• To make a vegetarian version, omit the bacon and sauté the vegetables in olive oil instead.
• Serve with a side of fresh fruit—the natural sweetness pairs nicely with the casserole’s savory flavors.

Recipe Card

Bacon, Mushroom and Spinach Breakfast Casserole

A hearty breakfast casserole full of flavor and easy to prepare.

Servings:
4 -6

Author: Malinda Linnebur

Prep Time:
20 mins

Cook Time:
45 mins

Total Time:
1 hr 5 mins

Ingredients

• 6 strips thick-cut bacon
• 1 cup sliced mushrooms
• 1/4 cup chopped onion
• 1 clove garlic, minced
• 8 eggs
• 1/3 cup milk
• 1 1/2 cups frozen hash browns
• 1 cup roughly chopped spinach
• 1 cup grated Swiss cheese
• 1/4 cup grated Parmesan cheese

Instructions

• Preheat oven to 350°F. Lightly grease a 1 1/2‑quart baking dish and set aside.
• In a large skillet, cook bacon over medium to medium-low heat until crispy. Drain on paper towels. Leave 2 tablespoons of bacon grease in the skillet, then add mushrooms and onion and cook 5–7 minutes until lightly browned. Add garlic and cook 1–2 minutes. Remove from heat and crumble the bacon.
• Whisk eggs and milk in a large bowl. Add crumbled bacon, hash browns, spinach, cheeses, and the mushroom mixture; stir to combine. Pour into the prepared baking dish and bake about 45 minutes, or until the center is set. Let rest briefly before serving.