Beat together eggs, milk, salt and pepper with a fork.
Make one omelet at a time. Heat 8 inch (20cm) non-stick skillet over medium-high heat.
Add 1 tsp (5ml) butter.
When melted, pour in 1/2 cup (125ml) egg mixture.
As eggs begin to set at the edges, use a spatula to gently push cooked portions to the center, tilting the skillet to allow the uncooked egg to flow into empty spaces.
When egg is almost set on surface but still looks moist, fill half of omelet with vegetable and sprinkle with 2 tbsp (30ml) cheese.
Slip spatula under unfilled side, fold over filling and slide onto serving place.