Pepperoni Stuffed Zucchini

Preheat oven to 375 degrees F (190 degrees C).
Cut zucchini in half lengthwise. With a metal spoon, scoop out most of the insides and place into a skillet. Transfer the zucchini shells to a baking sheet.
Place the skillet over medium heat, and stir in onion and pepperoni. Cook about 3 minutes. Remove from heat, and spoon into zucchini shells. Sprinkle with cheese.
Bake in preheated oven for 12 minutes.