Start by washing and finely chopping your bell peppers and onions. I like to keep everything uniform in size so each muffin has a balanced flavor in every bite. Pre-grating the cheese also saves time later.
In a mixing bowl, crack the eggs and add the milk, salt, and pepper. I whisk them until fully combined and slightly frothy—it makes the muffins light and airy.
Gently fold in the diced peppers, onions, and shredded cheese into the egg mixture. I try not to overmix; just enough to distribute the ingredients evenly.
Spray or lightly grease the muffin tin and pour the mixture evenly into each cup. I usually fill them about 3/4 full so they have room to rise without spilling over.
Bake in a preheated oven at 180°C (350°F) for 20 minutes, or until a toothpick inserted comes out clean. I find that keeping an eye on the last few minutes ensures they don’t overcook and stay moist.
Once baked, let them cool for a few minutes before removing from the tin. I like to garnish with fresh herbs or a little extra cheese for presentation.