Step 1: Preheat the Air Fryer

Preheat your air fryer to 325°F (163°C). This lower temperature allows the eggs to cook evenly without drying out.

Step 2: Whisk the Eggs In a bowl, whisk the eggs with salt, pepper, and a splash of milk if using. Whisk until fully combined and slightly frothy.

Step 3: Add the Fillings Stir in bell peppers, onions, spinach, and any cooked protein you’re using. Make sure proteins are fully cooked before adding.

Step 4: Prepare Your Dish

Lightly grease an oven-safe dish, silicone mold, or parchment-lined pan that fits inside your air fryer basket. Pour in the egg mixture, keeping the dish shallow for even cooking.

Step 5: Add the Cheese Layer Gouda slices on top or mix chopped cheese directly into the eggs for a more uniform melt.

Step 6: Cover and Cook

Cover the dish loosely with foil to prevent the top from browning too quickly.Air fry for 20–25 minutes.

At the 20-minute mark, remove the foil and check doneness with a toothpick. If the center is still soft, cook for another 3–5 minutes.

Step 7: Cool and Serve Let the frittata rest for 1–2 minutes, then slice and serve warm.