Preheat large Dutch oven or heavy bottom pot on medium-high heat and add 3 tablespoons of olive oil. Then add bell peppers, onion, 3 minced garlic cloves and saute for 5-7 minutes, stirring occasionally.
Add eggplant and remaining 2 tablespoons of olive oil. Saute for another 5-7 minutes, stirring occasionally.
Add zucchini, tomatoes, balsamic vinegar, sugar, Italian seasoning, salt and pepper. Stir, cover and bring to a boil. Then reduce heat to low and simmer ratatouille for 25-30 minutes, stirring a few times.
Turn off heat and let it stand covered for 1 hour. Then add remaining 1 grated garlic clove and fresh basil. Stir and serve hot or cold with crusty bread or along fish, chicken, grilled meats, or on top of crostini.
Notes
Store: Refrigerate leftovers in an airtight container for up to 5 days.Freeze: Freeze in an airtight container for 3 months. Thaw in the fridge overnight and reheat by simmering in a pot on low heat while covered, stirring a few times.