Heat the oil in a large saucepan over medium heat. Add the garlic, onion, bay leaf, oregano, tarragon, thyme, savory, fennel seeds and ground coriander and cook, stirring, until soft and fragrant.
Add the eggplant and cook, stirring occasionally, until soft, about 8 minutes. Add the zucchini, bell peppers, and tomatoes and cook, stirring occasionally, until tender, about 7 minutes. Season with salt and pepper, to taste.
The ratatouille may be made 1 day in advance, kept covered and chilled, and reheated before serving.