In a small bowl, whisk egg whites, water and pepper until blended; stir in ham, green pepper and onion. Heat a large skillet coated with cooking spray over medium-high heat. Pour in egg white mixture. Mixture should set immediately at edges. As egg whites set, push cooked portions toward the center, letting uncooked egg flow underneath., When no liquid egg remains, sprinkle goat cheese on 1 side. Fold omelet in half; slide onto a plate. If desired, sprinkle with parsley.