Cheese Omelet

1. Crack the eggs on a flat, hard surface and open them into a medium bowl. Add the milk if you’re using it, whisk until the yolks and whites are just combined, and sprinkle with some salt and pepper.
2. Put the 2 tablespoons butter into a medium skillet, preferably nonstick, over medium-high heat. When it has melted, swirl it around the pan until the bottom is coated and the foaming stops.
3. Pour the egg mixture into the pan and cook, undisturbed, for about 30 seconds, then use a wooden spoon or rubber spatula to gently push the outer edges of the eggs toward the center. As you do this, tip the pan to allow the uncooked eggs in the center to spread into the gaps and cook. Continue this process until the omelet is mostly set around the edges but still quite runny in the center, a total of about 3 minutes (if you like well-done eggs, cook until the center firms up, another 1 or 2 minutes).
4. Lower the heat to medium and sprinkle the cheese over the eggs, mostly toward the center. If the eggs still look too wet inside after folding, continue to cook just until the eggs are no longer runny. Slip a spatula halfway under one side and fold the omelet in half. Hold it in place for a moment, until the eggs and filling set. Slide the omelet out of the pan and onto a plate, smear the remaining 1 teaspoon butter over the top (it will melt), cut in half crosswise, and serve.

—Recipe from How to Cook Everything: The Basics