Preheat oven to 375. Wipe mushrooms clean and remove stems. Place in a medium size glass baking dish. Trim ends from stems and add to dish or reserve for another use.
Put one frozen meatball in the stem cavity. Sprinkle cumin over meatballs and mushrooms.
Drizzle teryaki sauce over all. Any excess teriyaki sauce will run into bottom of the pan.
Place pan in oven and bake 35-45 minutes or until mushrooms are tender and cooked through. Serve immediately.
As an alternative to stuffing the mushrooms, you can cut them in quarters and place in the pan, scatter meatballs in the pan, top all with cumin and teriyaki sauce. Bake 25-30 minutes and serve as a side dish.