Easy Customizable Egg Muffins

Preheat your oven to 350°F (175°C). Generously grease all 12 cups of a standard muffin tin with cooking spray or oil. This is non-negotiable for easy release—trust me, you don't want to be scraping stuck egg out later.

In a large bowl, whisk together the eggs, milk, salt, and pepper until the mixture is completely uniform and slightly frothy. This aeration is key for a light, fluffy texture. Don't just stir; whisk vigorously for a good 30 seconds.

Divide your chosen fillings—the diced vegetables, shredded cheese, and cooked meat—evenly among the 12 prepared muffin cups. Aim for each cup to be about 2/3 full with fillings to leave room for the egg mixture.

Carefully pour the whisked egg mixture over the fillings in each cup, filling them almost to the top. A liquid measuring cup with a spout makes this clean and easy. Gently tap the tin on the counter to release any large air bubbles.

Bake for 18-22 minutes, or until the egg muffins are completely set in the center and the tops are lightly golden. A toothpick inserted should come out clean. Let them cool in the tin for 5 minutes before running a knife around the edges to pop them out.