In An Ungreased 2-Qt. Microwave-Safe Dish, Combine The Beef, Onion And Garlic. Cover And Cook On High For 5 Minutes Or Until Meat Is No Longer Pink, Stirring Once; Drain. Stir In Tomato Sauce, Water, Chili Powder, Salt And Pepper. Cover And Cook On High For 8 Minutes, Stirring Once. In An Ungreased 1-1/2-Qt. Round Dish, Layer One Tortilla, 1/2 Cup Meat Sauce And 1/2 Cup Cheese. Repeat Layers Three Times. Heat, Uncovered, On High For 1 Minute Or Until The Cheese Is Melted.