1. Wipe mushroom tops off with a wet towel and pick out the stems.
2. In a medium skillet on medium-high heat, cook turkey meat through.
3. Add chopped onions and seasonings.
4. Cook until just about done, remove from heat and drain.
5. Add 2 cups of cheese and mix together.
6. Spoon mixture into mushrooms and place them on a baking pan or cookie sheet.
7. Top with reserved cup of cheese.
8. Place in 350 F oven for about 15 to 20 minutes, or until cheese is melted and mushrooms are soft.