Preheat oven to 425°F

Take a 8x8 baking dish or 9x13, depends how big your chicken breasts are (mine were fairly small), you can spray it with cooking spray if you want, but I didn't, and carefully place the chicken in the dish. Spoon some of the leftover salsa (from the crockpot) over the chicken and sprinkle evenly with the cheese.

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