Grilled Marinated Portobello Mushrooms

1. Combine oil, lemon juice, garlic, and salt in 1-gallon zipper-lock bag. Add mushrooms and toss to coat; press out as much air as possible and seal bag. Let sit at room temperature for 1 hour.
2. Meanwhile, cut four 12-inch-square pieces of aluminum foil (or six 9-inch-square pieces if using smaller mushrooms).
   3A. FOR A CHARCOAL GRILL: Open bottom vent completely. Light large chimney starter three-quarters filled with charcoal briquettes (4-1⁄2 quarts). When top coals are partially covered with ash, pour evenly over grill. Set cooking grate in place, cover, and open lid vent completely. Heat grill until hot, about 5 minutes.
   3B. FOR A GAS GRILL: Turn all burners to high, cover, and heat grill until hot, about 15 minutes. Turn all burners to medium-high.
3. Clean and oil cooking grate. Remove mushrooms from marinade and place each on a foil square, gill side up. Fold foil around each mushroom and seal edges. Place foil packets on grill, sealed side up, and cook (covered if using gas) until juicy and tender, 9 to 12 minutes.
4. Using tongs, unwrap mushrooms, place gill side up on grill, and cook until grill-marked, 30 to 60 seconds. Transfer to serving platter and serve.

GRILLED MARINATED PORTOBELLOS WITH TARRAGON
Substitute 2 teaspoons rice vinegar for lemon juice, reduce garlic to 1 clove, and add 1 tablespoon chopped fresh tarragon to marinade.