In a small skillet, heat the oil over medium heat. Add the onions, tomatoes, spinach and a pinch salt. Cook until the onion is soft, about 3 to 5 minutes. Add pepper, to taste, and another pinch salt; and cook for another minute. Remove the spinach mixture from the heat to a bowl. Cover and keep warm.
In a medium bowl, whisk the egg whites, water, and a pinch salt and pepper until frothy. Lightly coat a medium nonstick skillet or omelet pan with cooking spray and heat the skillet over medium heat. Add 1/4 of the egg whites, swirling to evenly cover the bottom of the pan. Cook until set, about 1 1/2 to 2 minutes. Using a rubber scraper lift the eggs up and let the runny uncooked egg flow underneath. Spoon 1/4 of the spinach mixture onto half of the omelet, fold over, and slide onto a serving plate. Repeat with remaining egg whites and spinach mixture.
This recipe was provided by professional chefs and has been scaled down from a bulk recipe provided by a restaurant. The Food Network Kitchens chefs have not tested this recipe, in the proportions indicated, and therefore, we cannot make any representation as to the results.
Recipe courtesy of The Deen Brothers