Grilled Three Cheese Potatoes

6 lg potatoes, sliced 1/4 inch thick
2 medium onions, chopped
1/3 cup grated Parmesan cheese
1 cup shredded sharp cheddar cheese, divided
1 cup shredded mozzarella cheese, divided
1 pound sliced bacon, cooked and crumbled
1/4 cup butter or margarine, cubed
1 tbsp minced fresh or dried chives
1 to 2 tsp seasoned salt
1/2 tsp pepper

Divide the potatoes and onions equally between two pieces of heavy duty foil (about 18-inch square) that have been coated with nonstick cooking spray. Combine Parmesan cheese and 3/4 cup each cheddar and mozzarella; sprinkle over potatoes and onions. Top with bacon, butter, chives, seasoned salt and pepper. Bring opposite ends of foil together over filling and fold down several times. Fold unsealed ends toward filling and crimp tightly. Grill, covered, over medium heat for 35-40 minutes or until potatoes are tender. Remove from the grill. Open foil carefully and sprinkle with remaining cheeses. Yield: 6-8 servings