Crack the eggs into a bowl and add milk, salt, and pepper. Whisk until well combined.
Heat a non-stick skillet over medium heat and add butter or oil.
Pour the egg mixture into the skillet, tilting to cover the surface.
Cook for about 2 minutes until the edges start to set.
Add bell peppers, onions, and cheese on one half of the omelet.
Use a spatula to fold the omelet in half over the fillings.
Cook for another 1-2 minutes until the cheese melts.
Slide the omelet onto a plate and garnish with fresh herbs.
Serve immediately and enjoy!