1. Whisk eggs and water in a bowl until just combined. In a separate bowl, combine cheese, tomatoes and 2 tablespoons of parsley.
2. Pour half the egg mixture into a non-stick frypan to just cover the base. Cook over medium heat until eggs are almost set. Place half the cheese mixture over the omelette and fold in half. Slide onto a serving dish, keep warm, and repeat with remaining mixture to make another omelette.
3. Heat non-stick frypan and add mushrooms and water and saute; until cooked through. Season to taste and stir in remaining parsley. Serve mushrooms on the Cheesy Omelette sprinkled with chopped parsley.