Prepare Your Ingredients
Begin by slicing your mushrooms, cutting your bell peppers into thin strips, and shaping your zucchini into quarter moons. If your cheddar cheese isn’t already shredded, shred it now. Having all your ingredients prepped beforehand, known as “mise en place,” ensures a smoother cooking process.

Sauté Your Vegetables
Heat the olive oil in an oven-safe, non-stick skillet over medium heat. Once the oil is shimmering, add the sliced mushrooms, bell peppers, and zucchini. Sauté for about 5-7 minutes, or until they are tender and slightly softened. This step helps to cook out excess moisture and concentrates their flavors, preventing a watery frittata.

Whisk the Eggs and Cream
While the vegetables are cooking, crack the large eggs into a separate large bowl. Add the heavy cream (or your chosen milk), sea salt, and black pepper. Whisk everything together thoroughly until well combined. Be careful not to overbeat the mixture; a gentle whisk is sufficient to incorporate the ingredients and ensure a tender, airy texture.

Combine and Bake the Keto Frittata
Once the vegetables are tender, spread them evenly across the bottom of the skillet. Sprinkle about half of the shredded cheddar cheese over the vegetables. Carefully pour the whisked egg and cream mixture over the vegetables and cheese. Gently shake the skillet to ensure the egg mixture settles evenly. Transfer the skillet to a preheated oven. Bake for approximately 20-25 minutes, or until the frittata is set and the edges are lightly golden brown.

Cool and Serve Your Delicious Keto Frittata
After baking, remove the skillet from the oven. Allow the frittata to cool in the skillet for 5-10 minutes. This resting period is crucial as it allows the frittata to fully set, making it much easier to slice neatly. Once slightly cooled, slice it into wedges and serve. The frittata is wonderful served warm, but also tastes fantastic at room temperature, making it an excellent option for meal prep.