Cooking Instructions

1. Prepare a charcoal or gas grill for indirect cooking, firing briquets or lighting the gas on one side of the grid only.
2. Place the mushrooms and onions on a large tray. In a glass measuring cup, mix the oil, rosemary, and garlic. Press the garlic with the back of a spoon to extract the juice. Drizzle over the mushrooms and onions; rub to coat evenly. Season lightly with salt. Set aside.
3. Place the onions directly over the heat source. Cook for 2 minutes each side, turning carefully, or until golden. Move the onions to the side away from the heat.
4. Place the mushrooms, underside facing up, directly over the heat source. Cook for 1 minute each side. Stack over the onions, underside facing up. Lay the bread slices on the tray. Rub both sides with any remaining oil. Place the slices directly over the heat source. Cook for 30 to 40 seconds each side, or just until golden. Remove to the tray; sprinkle evenly with the Parmesan. Set aside.
5. Cover the grill and cook for 10 to 12 minutes, or until juices start to pool in the mushrooms. Remove the mushrooms and onion to a serving platter. Place the bread slices, cheese side up, on the side of the cooking rack away from the direct heat source. Cover and grill for 5 minutes, or until hot.