Mushroom and Feta Breakfast Casserole

Start your morning with this savory and satisfying Mushroom and Feta Breakfast Casserole, a wholesome dish packed with earthy cremini mushrooms, vibrant spinach, and creamy crumbled feta cheese. This easy breakfast bake combines the richness of eggs and milk with the hearty texture of whole grain or sourdough bread, creating a golden, fluffy casserole that’s perfect for brunch gatherings or meal prep. Infused with aromatic garlic, onion, and a touch of dried oregano, every bite delivers layers of flavor. With minimal prep and a bake time under 40 minutes, this crowd-pleasing vegetarian casserole is a deliciously simple way to elevate your mornings. Serve it warm for a comforting start to your day or pair it with a light salad for a balanced meal any time.

Nutriscore Rating: 68/100

Prep Time:15 mins

Cook Time:35 mins

Total Time:50 mins

Servings: 6

Ingredients

• 2 tablespoons olive oil
• 1 medium, diced yellow onion
• 2 cloves, minced garlic
• 8 ounces, sliced cremini mushrooms
• 4 cups, packed baby spinach
• 8 large eggs
• 1 cup milk (any type)
• 1 teaspoon salt
• 0.5 teaspoon black pepper
• 0.5 teaspoon dried oregano
• 4 ounces crumbled feta cheese
• 4 slices, cut into cubes bread slices (preferably whole grain or sourdough)
• 1 tablespoon, for greasing butter or cooking spray

Directions

Step 1

Preheat your oven to 375°F (190°C) and grease an 8x8-inch baking dish with butter or cooking spray.

Step 2

In a large skillet over medium heat, add the olive oil and heat until shimmering.

Step 3

Add the diced onion and sauté for 3–4 minutes until softened and translucent.

Step 4

Stir in the minced garlic and cook for 30 seconds, until fragrant.

Step 5

Add the sliced mushrooms to the skillet and sauté for 5–6 minutes, until they release their moisture and begin to brown.

Step 6

Stir in the baby spinach and cook for 1–2 minutes, just until wilted. Remove the pan from heat and set aside.

Step 7

In a large mixing bowl, whisk together the eggs, milk, salt, black pepper, and dried oregano until fully combined.

Step 8

Lightly fold the bread cubes into the egg mixture, ensuring they are evenly coated.

Step 9

Add the sautéed mushroom-spinach mixture and crumbled feta cheese to the bowl, folding gently to combine.

Step 10

Pour the mixture into the prepared baking dish and spread it out evenly.

Step 11

Bake in the preheated oven for 30–35 minutes, or until the top is golden and the casserole is set in the center.

Step 12

Remove from the oven and let the casserole cool for 5 minutes before slicing and serving.

Nutrition Facts

Serving size	(1632.7g)

Amount per serving	% Daily Value*
Calories	1925.3

Total Fat 107.3g	0%
Saturated Fat 41.6g	0%
Polyunsaturated Fat 2.7g
Cholesterol 1623.8mg	0%
Sodium 5881.5mg	0%
Total Carbohydrate 131.4g	0%
Dietary Fiber 20.9g	0%
Total Sugars 30.7g
Protein 110.0g	0%

Vitamin D 470.3IU	0%
Calcium 1391.2mg	0%
Iron 23.9mg	0%
Potassium 2295.5mg	0%

*The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.

Source of Calories

Fat: 50.0%

Protein: 22.8%

Carbs: 27.2%