This sound absolutely scrumptious (from Campbell’s Kitchen):

 

Pan-Grilled Veggie & Cheese Sandwiches

2 Portobello mushrooms, cut into ½" slices

2 slices onion, ½" thick each

1 red pepper, cut into strips

8 slices eggplant, ¼" thick each

Garlic powder (optional)

½ C shredded fat-free mozzarella cheese

8 slices Whole Wheat Bread

2 TBS balsamic vinegar

 

Spray nonstick grill pan or nonstick skillet with vegetable cooking spray; heat over medium heat. Add the mushrooms, onion and pepper to one side of the pan; add eggplant. Sprinkle garlic powder over all. Cook until browned and tender. Sprinkle eggplant with cheese and cook until melted. Arrange eggplant slices on four slices of bread. Toss mushrooms, onion and pepper with vinegar. Top the eggplant with mushroom mixture and remaining bread. (Serves four).