Microwave Tuna Casserole Recipe

In a small bowl, combine the sour cream, mayonnaise, and mustard. Mix well. In a large bowl, combine the noodles and tuna. Stir in the sour cream mixture. Spoon into a microwave-safe dish. Microwave uncovered on high for 6-8 minutes. Sprinkle with cheese and tomato. Microwave for two minutes longer. Note: If you like a creamier sauce, you can double the amount of sour cream, mayonnaise, and mustard.