Saute sliced mushrooms and garlic in butter over medium heat until soft and browned.

Meanwhile, while mushrooms are cooking, beat eggs in bowl until well mixed.

Melt butter in separate pan over medium heat, then add eggs.

When eggs start to become firm, lift one edge with spatula and pour in about two tablespoon water under your eggs.

Cover pan, and the water will turn to steam and cook the top of your omelet. (No flipping -- yay!)

Leave pan covered and continue cooking over medium heat for two minutes, then remove cover carefully (watch for steam!).

Sprinkle cheddar cheese across entire top of your eggs.

Then, add mushrooms and feta only on one half. Fold omelet over mushroom/feta mixture.

Turn off the heat under your pan and leave the omelet in the warm pan for a couple of minutes to allow the cheeses to melt -- then serve!