2 large tomatoes (about 1 pound), halved and sliced 1/2 inch thick
1 medium eggplant (1 pound), cut into 1-inch dice
1/2 pound zucchini, sliced crosswise 1 inch thick
1 medium red bell pepper, cut into 1-inch pieces
1 bay leaf
Salt and freshly ground pepper
Heat the olive oil in a large, deep skillet. Add the onion and cook over moderate heat until softened, about 5 minutes. Add the garlic and cook for 1 minute. Reduce the heat to moderately low and add the tomatoes, eggplant, zucchini, bell pepper and bay leaf. Season with salt and pepper, cover and cook, stirring occasionally, until the vegetables are very tender, about 1 hour. Discard the bay leaf and serve warm or at room temperature.
The ratatouille can be refrigerated for 3 days.
Look for a clean, crisp white to contrast with the sharp eggplant and sweet onions. Inexpensive, citrusy dry examples from the Côtes de Gascogne are excellent choices.