Cook ground beef in a skillet over medium heat and break up the pieces as it cooks until the meat is browned. Drain grease if needed. Remove beef, and saute the small onion the skillet until translucent. Add beef, chili powder, cumin and salt, and cook for approximately 5 minutes.
Place rinsed beans in a bowl and mash about ¾ of them with a fork. Add beans, tomato sauce, water and salsa to the skillet.
Bring to a boil and then reduce heat and let simmer until the liquid has evaporated.
Remove from heat and add the cheese. Stir until cheese is melted.
Serve with your favorite taco toppings (tomatoes, lettuce, cheese, etc) so that everyone can make their own taco to their liking.