Grilled Portobello with Basil Mayonnaise Sandwich

• 1/3 cup balsamic vinegar
• 1/4 cup olive oil
• 1 tablespoon minced garlic
• 6 portobello mushroom caps
• 1/2 cup mayonnaise
• 1 tablespoon Dijon mustard
• 1 teaspoon lemon juice
• 2 tablespoons chopped fresh basil
• 6 kaiser rolls, split, toasted
• 1 tablespoon butter
• 6 leaves lettuce
• 6 tomato slices

1. Preheat an outdoor grill for medium heat, and lightly oil the grate.
2. Whisk together the balsamic vinegar, olive oil, and garlic in a small bowl.
3. Arrange the portobello mushrooms gill-side up on a tray or baking sheet.
4. Brush the mushrooms with some of the vinegar mixture, and allow to marinate for 3 to 5 minutes.
5. Place the marinated mushrooms on the preheated grill, gill-side down.
6. Grill mushrooms until tender, brushing both sides of the mushrooms with the remaining marinade, about 4 minutes on each side.
7. Mix the mayonnaise, dijon mustard, lemon juice, and basil in a small bowl.
8. Butter the toasted kaiser rolls, then spread with the mayonnaise mixture.
9. Divide the mushrooms, lettuce, and tomato slices evenly to make 6 sandwiches.

balsamic vinegar, olive oil, garlic, portobello mushroom caps, mayonnaise, mustard, lemon juice, fresh basil, kaiser rolls, butter, leaves lettuce, tomato slices

Taken from allrecipes.com/recipe/grilled-portobello-with-basil-mayonnaise-sandwich/ (may not work)