High Protein Breakfast Casserole: Sausage Frittata with Spinach and Mushrooms

This Sausage Frittata with Spinach and Mushrooms is a high-protein, low-carb breakfast casserole perfect for meal prep or feeding a crowd. With just six simple ingredients, this one-pan recipe is quick to make and packed with flavor. Gluten-free and keto-friendly, it’s a versatile dish for breakfast, brunch, or even a light lunch or dinner.

Why You’ll Love This Recipe

• Protein-packed: With eggs, sausage, and cheese, it’s a satisfying and energy-boosting meal.
• Versatile: Easily adaptable with different veggies, cheeses, or sausage varieties.
• Make-ahead friendly: Ideal for meal prep, brunch parties, or quick weekday breakfasts.
• Low-carb and keto: Naturally gluten-free and perfect for those watching their carbs.

Ingredients

(Tip: You can find the complete list of ingredients and their measurements in the recipe card below.)

• 16 oz crumbled breakfast sausage (e.g., Jimmy Dean’s)
• 8 oz mushrooms (baby Bella or crimini), sliced
• 5 oz fresh spinach
• 8 large eggs
• 3/4 cup heavy cream (or half-and-half)
• 1 cup sharp cheddar cheese, shredded
• Salt and pepper, to taste

Directions

Step 1: Preheat and Cook Sausage

1. Preheat your oven to 375°F (190°C).
2. Heat a 10- or 12-inch cast iron skillet over medium heat. Add the sausage and cook, crumbling it as it cooks, until browned and fully cooked. Drain any grease and remove the sausage from the skillet, setting it aside in a bowl.

Step 2: Cook Vegetables

1. In the same skillet, add the sliced mushrooms. Season generously with salt and pepper and cook for about 3 minutes, until they release their juices and soften.
2. Add the spinach and sauté until wilted. Return the cooked sausage to the skillet, stirring to combine.

Step 3: Prepare the Egg Mixture

1. In a bowl, whisk together the eggs and heavy cream until fluffy. Season with a pinch of salt and pepper.

Step 4: Assemble and Bake

1. Pour the egg mixture evenly over the sausage, spinach, and mushrooms in the skillet. Sprinkle the shredded cheddar cheese over the top, pressing some into the egg mixture.
2. Transfer the skillet to the oven and bake for 15–20 minutes, or until the frittata is set and no longer wobbly in the center.

Step 5: Rest and Serve

1. Carefully remove the skillet from the oven using oven mitts. Let the frittata rest for 10–15 minutes before slicing and serving.

Servings and Timing

• Servings: 10
• Prep Time: 10 minutes
• Cook Time: 20 minutes
• Total Time: 30 minutes

Variations

• Vegetarian: Omit the sausage or use plant-based sausage. Double the mushrooms or add other veggies like bell peppers or zucchini.
• Cheese options: Substitute cheddar with Monterey Jack, Swiss, or feta for a different flavor profile.
• Different greens: Swap spinach with kale, Swiss chard, or arugula.
• Spicy kick: Use hot sausage or add red pepper flakes for a spicier dish.
• Mini frittatas: Use a muffin tin for individual servings—great for grab-and-go breakfasts.

Storage/Reheating

• Storage: Store leftovers in an airtight container in the refrigerator for up to 4 days.
• Freezing: Cool completely, then wrap individual slices in plastic wrap and freeze for up to 2 months.
• Reheating: Reheat slices in the microwave for 1–2 minutes or in a 350°F oven until warmed through.

FAQs

1. Can I use milk instead of heavy cream?

Yes, you can use milk, but reduce the amount to 1/2 cup to avoid making the frittata too watery.

2. What type of sausage works best?

Breakfast sausage, mild or spicy Italian sausage, or even chicken sausage works well.

3. Can I make this in a baking dish instead of a skillet?

Yes, use a greased 9×13-inch baking dish and bake for 20–25 minutes.

4. How do I keep the frittata from sticking to the skillet?

Ensure your skillet is well-seasoned or use a nonstick, oven-safe skillet. Grease it lightly before adding ingredients.

5. Can I make this frittata dairy-free?

Yes, use a plant-based milk alternative and dairy-free cheese.

6. How do I know when the frittata is done?

The center should be set and no longer wobbly. A knife inserted into the middle should come out clean.

7. Can I add potatoes?

Yes, add diced and pre-cooked potatoes for a heartier option.

8. Can I double this recipe?

Yes, double the ingredients and bake in a larger pan to accommodate.

9. Can I serve this cold?

Yes, it’s delicious cold or at room temperature, making it great for picnics or packed lunches.

10. What should I serve with this frittata?

Pair it with a side salad, fresh fruit, or crusty bread for a complete meal.

Conclusion

This Sausage Frittata with Spinach and Mushrooms is a versatile, protein-packed breakfast casserole that’s perfect for any occasion. With minimal prep time and simple ingredients, it’s a dish you’ll want to make again and again. Whether you enjoy it fresh from the oven, reheated during the week, or cold on a picnic, this frittata is a true crowd-pleaser!

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