1. Heat 1 teaspoon oil in 10-inch nonstick skillet over medium heat. Add shallot; cook until soft, stirring well. Add spinach; sauté until wilted (2 minutes), stirring well. Transfer to bowl; stir in ricotta and 3 tablespoons salsa.
2. Heat 2 teaspoons oil in skillet over medium heat. Combine eggs, egg whites, and water in a bowl. Whisk until well-blended. Add salt and pepper; whisk 5 seconds.
3. Pour egg mixture into skillet; cook 10 seconds or until edges are set. Pull in cooked edges using a spatula; tip pan and rotate until there is just a little uncooked egg in the middle (about 5 minutes).
4. Add spinach mixture evenly to top of omelet; sprinkle with cheese. Cook 20 seconds; remove from heat. Run spatula around omelet edges. Fold omelet in half, and let slide onto serving platter. Serve immediately with additional salsa, if desired.