Grilling vegetables in foil packets seals in moisture for tasty, tender sides hot off the barbecue -- and you won't have to wash a single dish.
Place mushrooms on a large piece of parchment-lined foil. Drizzle with olive oil and season with salt and pepper. Fold into a tight packet and grill over medium-high until mushrooms are tender, 12 to 15 minutes. Sprinkle with basil.