Slice 2 eggplants lengthwise ¼ inch. Brush with mixture of 2 Tb oil, 2 tsp balsamic vinegar and 1 tsp Dijon mustard. Grill until cooked. Stack eggplant together to form shape of burger. Top with Provolone Cheese and fresh basil. Brush buns with olive oil and toast on grill. Salt and pepper to taste and enjoy.