1. Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius). Crumble or cube the feta cheese.
2. Combine with mushrooms and cottage cheese. Stuff into shells.
3. Arrange in a 9- x 13-inch (23- x 33-cm) baking pan. Sprinkle with garlic powder, then shredded mozzarella.
4. Cover and bake for 30 minutes, then uncover and bake for another 30 minutes. Enjoy!