Cook the beef in a 10-inch skillet over medium-high heat until it's well browned, stirring often. Pour off any fat.
Stir the soup, salsa, water, and tortillas in the skillet and heat to a boil. Reduce the heat to low. Cook for 5 minutes or until the beef mixture is hot and bubbling. Stir the beef mixture. Top with the cheese.
Creamy Mexican Fiesta: Stir in 1/2 cup sour cream with the soup.
Ranchero Style: Use corn tortillas instead of flour tortillas and shredded Mexican cheese blend instead of Cheddar.
Serving Suggestion: Serve with a mixed green salad with Italian salad dressing and corn-on-the-cob. For dessert serve store bought flan.