Heat oil in a heavy, large Dutch oven over medium heat.
Add garlic; stir 1 minute.
Add eggplant, green bell peppers, tomatoes, onion, zucchini and basil.
Saute for 5 minutes. Cover and simmer until all vegetables are tender, stirring occasionally, about 25 minutes.Uncover pot and simmer until juice thickens, stirring occasionally, about 10 minutes.
Mix in vinegar; season to taste with salt and pepper.Preheat oven to 350 degrees.
Spread in 9-inch pie dish.
Sprinkle with cheese, if desired.
Bake until heated through, about 20 minutes.This recipe yields about 3 cups.