Preheat oven to 400°. Salt and pepper the eggplant and toss with 1 Tbsp olive oil in a baking dish. Add water, cover and bake for about 40 minutes or until soft to the touch. Sauté the onions in 1 Tablespoon olive oil until they start to brown. Add the peppers, season with salt and pepper and cook until peppers and onions are well browned. Add the vinegar and garlic and cook one minute. Transfer the mixture to a bowl. Sauté the squash in 1 Tablespoon olive oil until it is brown on both sides. Add to the pepper and onion mixture.
Discarding the liquid in the baking dish, add the eggplant to the other vegetables. Return all to the sauté pan, add the tomatoes, bring to a simmer and cook for about two minutes. If it looks too juicy, pour off the excess liquid into another sauté pan, reduce it until thickened and add back to the vegetables. Allow it to cool. Add the capers, olives, herbs, a little more red wine vinegar, and salt and pepper if needed. Ratatouille keeps well refrigerated for several days and allegedly improves in flavor over time. It was so good, I didn’t give it a chance to age.