Cook onion and garlic in oil in large skillet for 2 minutes. Add peppers; cook 2 minutes. Add turkey sausage, breaking up with a wooden spoon; cook until turkey is cooked through, about 7 minutes.
Spread pasta sauce over each muffin; top with turkey mixture. Sprinkle with Cheddar.
Bake in 350 degree F oven 15 minutes or until cheese melts. Makes 8 pizzas.