1

Spray a large nonstick skillet with olive oil nonstick spray and set over medium heat. Add the mushrooms; cook, stirring, until golden, about 3 minutes. Transfer the mushrooms to a plate and wipe out the skillet with paper towels.

2

Beat the eggs, egg whites, water, salt, and pepper in a medium bowl. Return the skillet to medium-high heat and add 1⁄4 teaspoon of the oil. When hot, add half of the egg mixture and cook, occasionally lifting the edges of the egg and tilting the pan to allow the uncooked mixture to flow underneath, until the eggs are almost set, about 2 minutes. Sprinkle with 2 tablespoons of the cheese and half the mushrooms. Loosen the edges of the omelette with a spatula and fold one half over the other. Reduce the heat to low and cook until the eggs are set and the cheese begins to melt, about 1 minute more.

3

Remove the skillet from the heat, tilt the skillet, and slide the omelette onto a plate. Repeat with the remaining oil, egg mixture, cheese, and mushrooms. Sprinkle the omelettes with the chives, if using, and serve at once. Yields half of omelette per serving.