In a small bowl beat together the eggs, the water, and salt and pepper to taste. Set aside. Heat the butter in an 8-inch skillet over medium heat. Add the ham, the bell pepper, and the onion, and saute until tender, about 2 minutes. Pour in the egg mixture. As the mixture sets at the edges, with a spatula gently lift the cooked portion to allow the uncooked egg to flow underneath. Cook until the bottom is set and the top is almost set. Slip the spatula underneath the omelette and fold in half. Slide the omelette onto a warm plate.