BEAT eggs and water in small bowl until blended.
MICROWAVE butter in 9-inch glass pie plate on HIGH until melted, about 15 seconds. TILT plate to coat bottom evenly. POUR egg mixture into hot pie plate. COVER TIGHTLY with plastic wrap, leaving a small vent.
MICROWAVE on HIGH 1 3/4 to 2 minutes. Do not stir.
When top is thickened and no visible liquid egg remains, SEASON with salt and pepper, if desired. PLACE half of the cheese on one half of the omelet. FOLD omelet in half with turner; sprinkle with remaining cheese. MICROWAVE on HIGH 10 seconds or until cheese melts. SLIDE from pie plate onto serving plate. SERVE immediately with salsa.
The secret of success. A tight cover is essential to achieve a tender, easily rolled or folded omelet in the microwave. It makes stirring unnecessary, and it traps steam, which promotes even cooking.
Microwave ovens vary. Cook times may need to be adjusted.
This recipe is an excellent source of protein, vitamin A and choline, and a good source of vitamin D and folate.