Place chicken breasts and tomato sauce in a medium saucepan over medium high heat. Bring to a boil, then add the salsa, cumin, garlic and chili powder. Let simmer for 15 minutes.
With a fork, start pulling the chicken meat apart into thin strings. Keep cooking pulled chicken meat and sauce, covered, for another 5 to 10 minutes. Add hot sauce to taste and stir together. You may need to add a bit of water if the mixture is cooked too high and gets too thick.)