preheat grill for high heat. Lightly grease 4 large sheets of heavy-duty aluminum foil.
Stuff each mushroom with equal amounts green onions and pine nuts. Place 6 mushrooms on each piece of aluminum foil drizzle with olive oil and season with salt and pepper. seal foil around mushrooms forming 4 packets.
Place foil packets on preheated grill and cook 20 minutes or until mushrooms are tender. serve