Pierogi Pasta Shells

51 uncooked jumbo pasta shells
2 packages (32 ounces each) refrigerated mashed potatoes
2 tablespoons dried minced onion
1/2 teaspoon onion powder
1/2 teaspoon garlic powder
4 cups (16 ounces) shredded cheddar cheese, divided
1/2 cup chopped green onions

Cook pasta shells according to package directions; drain and rinse in cold water. Place mashed potatoes in a large microwave-safe bowl.

Cover and microwave on high for 4 minutes, stirring once. Add the minced onion, onion powder and garlic powder. Stir in 2 cups of cheese until blended.

Stuff into shells. Place in two greased 13-in. x 9-in. baking dishes. Sprinkle with green onions and remaining cheese.

Cover and bake at 350° for 20 minutes. Uncover; bake 10 minutes longer or until heated through. Makes 12 servings.