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This Swiss, Mushroom, and Spinach Frittata is a standout choice for anyone looking to elevate their breakfast or brunch routine with a dish that’s both comforting and nutritious.
What makes it special is the clever use of whipped egg whites, which creates a light and airy texture without sacrificing richness—thanks to the creamy Emmentaler cheese.
Packed with 15 grams of protein per serving and only 4 grams of carbs, this frittata is a great low-carb, high-protein option ideal for those watching their macros.
The baby spinach and mushrooms bring fiber, antioxidants, and essential minerals like iron and potassium, making this dish not just delicious, but genuinely wholesome.
Best of all, it’s incredibly versatile—equally suited for meal prep, quick weeknight dinners, or elegant weekend brunches.
It’s ready in just 25 minutes, making it a convenient go-to for busy lifestyles.
Must-Have Tools for Perfect Results
12-Inch Cast Iron Skillet
Lodge Pre-Seasoned Cast Iron Skillet
Perfect for stovetop-to-oven cooking, this skillet ensures even heat distribution and retains heat beautifully for a golden, puffed frittata. Beyond frittatas, it’s ideal for searing meats, baking cornbread, and more.
Electric Hand Mixer
KitchenAid 5-Speed Ultra Power Hand Mixer
Whipping the egg whites to stiff peaks is the secret to the frittata’s airy texture. This hand mixer makes the job fast and effortless—also great for whipping cream, mixing batter, or kneading soft doughs.
Large Mixing Bowls
Pyrex 3-Piece Glass Mixing Bowl Set
You’ll need separate bowls for whipping egg whites and mixing yolks with dairy and cheese. These versatile, microwave-safe bowls are a staple for any home chef.
Silicone Spatula
Di Oro Seamless Silicone Spatula Set
Gentle folding of egg whites is key to maintaining their volume. A flexible, heat-resistant spatula makes this delicate task easy, and it’s perfect for sautéing or scraping every last bit of batter.
Cheese Grater
OXO Good Grips Box Grater
Freshly shredded cheese melts better and distributes more evenly. This sturdy grater is ergonomic and efficient for shredding cheese, zesting citrus, or even slicing vegetables.
Mushroom and Swiss Cheese Frittata
Equipment
- (1) 12-inch Oven-Safe Skillet (nonstick or cast iron)
- (1) Electric Hand Mixer or Stand Mixer with Whisk Attachment
- 2 Large mixing bowls
- 1 Silicone Spatula
- (1) Cheese Grater
Ingredients
- 1 –2 tablespoons extra-virgin olive oil
- 8 ounces fresh button mushrooms thinly sliced (or substitute with crimini)
- 1 clove garlic finely minced
- 5 cups baby spinach leaves loosely packed
- 10 large eggs whites and yolks separated
- 1 cup half-and-half or whole milk
- 1 ¾ cups shredded Emmentaler cheese divided: 1½ cups for the batter, ¼ cup for topping
- 1 teaspoon kosher salt
- ½ teaspoon ground black pepper
Instructions
- Preheat the Oven: Position the oven rack in the middle or slightly above center. Preheat your oven to 400°F (200°C) so it’s ready for finishing the frittata.
- Sauté the Vegetables: In a large 12-inch oven-safe skillet, heat 1–2 tablespoons of olive oil over medium-high heat, just enough to coat the bottom. Add the sliced mushrooms and sauté for about 3–4 minutes until they release moisture and begin to brown. Lower the heat to medium-low and stir in the minced garlic, cooking for 30–60 seconds until fragrant. Gradually add the baby spinach, stirring in batches as it wilts. Once all the spinach is wilted, remove the skillet from heat and let the mixture cool slightly.
- Whip the Egg Whites: In a clean, dry mixing bowl, use an electric hand mixer or stand mixer with a whisk attachment to beat the egg whites until they form stiff peaks. This step creates the light, airy texture of the frittata.
- Prepare the Egg Yolk Mixture: In a separate bowl, whisk the egg yolks until smooth. Stir in the half-and-half (or milk), 1½ cups of shredded cheese, salt, and pepper. Mix until fully combined.
- Fold and Assemble the Frittata: Gently fold the whipped egg whites into the yolk mixture using a silicone spatula, being careful not to deflate the volume. Once blended, pour the egg mixture into the skillet over the cooked vegetables. Sprinkle the remaining ¼ cup of cheese evenly over the top.
- Bake Until Set and Golden: Transfer the skillet to the preheated oven and bake for 10–13 minutes, or until the frittata is puffed, golden on top, and the center is fully set. Avoid overbaking to keep the texture tender.
- Slice and Serve: Remove from the oven and let it sit for a few minutes before slicing. Cut into wedges and serve warm. Enjoy it solo or paired with a light salad or toast.
Notes
- Cheese Tip: Emmentaler provides a nutty richness and creamy melt that’s perfect for frittatas. If unavailable, substitute with Swiss or Gruyère cheese.
- Whipping the Egg Whites: This technique adds volume and fluffiness without the need for baking powder or flour—ideal for a gluten-free and airy result.
- Meal Prep Friendly: Store leftovers in an airtight container in the fridge for up to 5 days. To reheat, microwave briefly or warm in a low oven.
- Vegetable Variations: Feel free to swap or add vegetables like bell peppers, zucchini, or caramelized onions for seasonal variety.
- Cast Iron vs. Nonstick: A well-seasoned cast iron skillet holds heat well and browns beautifully, but a nonstick pan also works for easy cleanup.
Chef’s Secrets for Fluffy Frittata
The secret to this frittata’s beautifully airy texture lies in separating the eggs and whipping the whites to stiff peaks before folding them gently into the yolk mixture.
This extra step may seem small, but it transforms the frittata into something light, soufflé-like, and utterly satisfying.
Be sure to use a clean, dry bowl when whipping the whites—any trace of yolk or moisture can prevent them from reaching full volume.
Another tip: don’t rush the vegetables. Cooking the mushrooms until they release their moisture helps concentrate their flavor and prevents the frittata from becoming watery.
Lastly, remove the skillet from heat before adding the egg mixture to avoid prematurely cooking the bottom layer and creating uneven texture.
Serving Ideas to Elevate Meals
This savory frittata is incredibly versatile and can easily anchor any meal of the day.
For breakfast or brunch, pair it with crusty sourdough toast, roasted potatoes, or a fresh fruit salad. If serving it for lunch or dinner, it goes beautifully with a mixed greens salad drizzled with a lemon vinaigrette or a warm grain bowl with quinoa and roasted veggies.
Add a dollop of Greek yogurt or a spoonful of salsa for a pop of flavor.
It also makes a fantastic vegetarian main course when served alongside a bowl of creamy soup, like tomato bisque or butternut squash.
Best Storage and Reheating Tips
Frittatas are meal-prep friendly and keep very well in the refrigerator.
Once fully cooled, store leftovers in an airtight container and refrigerate for up to 5 days.
To reheat, microwave individual slices on medium power for 30–60 seconds, or place in a 300°F oven for 8–10 minutes to gently warm without drying out.
Avoid freezing, as the texture of the eggs can become rubbery after thawing.
If you’re planning to use it throughout the week, consider slicing it into portions ahead of time for easy grab-and-go breakfasts or lunches.
Frequently Asked Frittata Questions
1. Can I use different types of cheese?
Absolutely! While Emmentaler adds depth and nuttiness, feel free to substitute with Swiss, Gruyère, sharp cheddar, or even a blend of cheeses for a unique twist.
2. Do I have to whip the egg whites?
Whipping the egg whites adds volume and creates a lighter texture, but if you’re short on time, you can use whole eggs whisked together. The result will be denser but still tasty.
3. Can I make this dairy-free?
Yes, you can substitute the half-and-half with an unsweetened dairy-free milk (like almond or oat milk) and use a plant-based cheese alternative. Note that the texture and flavor may vary slightly.
4. Is this recipe gluten-free?
Yes, this recipe is naturally gluten-free, as it contains no flour or bread crumbs. Just double-check that your cheese and any seasoning blends used are certified gluten-free.
5. Can I make it ahead for a party?
Definitely! You can bake the frittata up to a day in advance, refrigerate it, and reheat gently in the oven before serving. It’s a crowd-pleaser for brunch buffets or potlucks.
This recipe is inspired by savorysimple and has been carefully refined to enhance clarity, streamline preparation steps, and ensure accurate results. We’ve also included health benefits, nutritional highlights, and Must-Have Tools to help you get the best results every time you cook.
