Place chicken breasts in slow cooker and pour the salsa to cover them. Cook between 1½ to 2 hours on high, don't cook longer because it will start to fall apart.

Preheat oven to 425 F degrees.

Spray a baking dish with cooking spray or grease and carefully place the chicken in the dish. Spoon the leftover salsa/sauce (from the slow cooker) over the chicken and sprinkle with the cheese.

Bake for 15 minutes or until it's nice and golden brown, and you see the sauce and cheese bubbling.