Rub the mushroom caps with a damp cloth to clean. Remove stems and reserve for Round 2 recipe "Stuffed Zucchini".
In a small bowl combine the grill seasoning, oil, garlic, Worcestershire sauce and vinegar. Brush over the mushrooms making sure to coat completely. Reserve 2 tablespoons of the marinade for the aioli.
Heat a grill pan or outdoor grill on medium heat. Put the mushrooms, gill side down, onto the grill and grill about 4 to 5 minutes on each side. After you flip the mushrooms top each with 2 tablespoons of Cheddar.
While the mushrooms are grilling, make the aioli sauce by combining the remaining 2 tablespoons of the marinade with the mayonnaise in a small bowl. Spread each hamburger bun with aioli sauce. Remove mushrooms from the grill and serve on the toasted buns with lettuce and tomato slices.
Recipe courtesy of Sandra Lee
Recipe courtesy of Rachael Ray