Season the meat with salt, pepper, garlic powder, and chili powder. Brown the meat, then on a microwave-safe plate, pile Doritos, meat, and queso. Heat the queso by placing the plate in the microwave for about 1 minute to 1 ½ minutes. Top with sour cream and, if desired, lettuce and tomatoes or guacamole.
Serves two, but for more servings, add ½ lb. of meat per person.