We grow eggplant, zucchini, bell peppers, and tomatoes in our summer vegetable garden. Those are most of the ingredients for ratatouille, a Mediterranean speciality in which these vegetables (along with onions, olive oil, thyme, and garlic) are cooked together on top of the stove until they break down completely and the flavors blend. Some recipes call for mashing the vegetables in a mortar when they are done.
Here's a way to make ratatouille in the oven, preserving the shape and texture of the different vegetables but getting good flavors at the same time. Cut eggplants, zucchini, and tomatoes into round slices. Arrange them in an oiled baking dish so that the slices are standing on end. Here I have red and yellow tomatoes, but all red tomatoes is fine of course. Add slices of bell peppers, red or green, if you want. Pack the dish pretty tightly. Alternate eggplant, zucchini, bell pepper, and tomato slices so that you have a good mixture.
When the baking dish is full, thinly slice a couple of cloves of garlic (more or less to taste) and insert the garlic slices between the vegetable slices so that garlic is spread all through the dish. Sprinkle on salt, pepper, and thyme to taste. Put in a couple of bay leaves if you want. And then drizzle olive oil over the whole thing.
Put the dish in a medium oven (325ºF -- that's 160ºC) for an hour or more, until all the vegetables are cooked and the kitchen smells like Provence. Serve hot, warm, or cold.
Here's a view out of our kitchen window in summertime.