The variety of vegetables you can use here is limited only by imagination. If you can eat it, you can probably grill it. Just try.
Any assortment of vegetables sliced 1/2" thick, for instance:
2 medium eggplant
3 or 4 zucchini
firm ripe tomato
1/2 cup each of balsamic vinegar and olive oil
salt, fresh ground pepper, and cayenne pepper to taste
1 tbsp each of chopped fresh basil, parsley, oregano and garlic
Combine vinegar, oil, seasonings and herbs till well blended. Brush over sliced vegetables and let marinated for 20 - 30 minutes. Grill lightly basting with marinade while cooking.
Serve hot off the grill.