Use a grill rack or secure onions with wooden toothpicks to keep them from separating during grilling.
- 1/4 cup plus 3 tablespoons olive oil, divided
- 6 tablespoons balsamic vinegar, divided
- 4 slices onion (1/4 inch thick)
- 1 teaspoon minced garlic
- 1/2 teaspoon dried basil
- 4 portobello mushroom caps
- 1 tablespoon honey
- 4 onion rolls, split
- 4 lettuce leaves
- 4 slices tomato
- 4 ounces fresh mozzarella cheese, cut into 1/4-inch slices
How to make it:
- In a resealable plastic bag, combine 1/4 cup oil and 2 tablespoons vinegar; add onion slices. Seal bag and turn to coat; marinate for 30 minutes. Meanwhile, in a small bowl, combine the garlic, basil and remaining oil. Brush over both sides of mushroom caps; set aside.
- In a small saucepan, bring honey and remaining vinegar to a boil; cook for 5 minutes or until thickened. Set aside.
- Drain and discard marinade from onions.
- Coat grill rack with nonstick cooking spray before starting the grill. Grill onions and mushrooms over medium heat for 10-12 minutes or until tender, turning frequently.
- Serve on rolls with lettuce, tomato and mozzarella. Drizzle with reserved balsamic-honey sauce.