In a 4-quart Dutch oven or saucepan, heat the olive oil over medium heat. First, add the garlic, peppers and onions and cook, stirring often, until the peppers and onions are softened, 6 to 7 minutes. Next, add the zucchini, tomatoes and eggplant; stir until coated with olive oil and garlic. Cook for 5 minutes, and then add the parsley, oregano, herbes de Provence if using, thyme and basil. Season with salt and pepper and stir to combine.
Finish cooking over lower heat for 8 to 10 minutes. Remove from the heat and let rest before serving for 10 minutes, to allow the flavors to incorporate. Use or cover and refrigerate for up to 5 days.