Gather eggplant, zucchini, yellow squash, tomatoes, onion, garlic, olive oil, salt, pepper, and herbs
Preheat the oven to 375°F
Slice the eggplant, zucchini, yellow squash, and tomatoes into thin rounds
Chop the onion and mince the garlic
Heat olive oil in a pan and cook the onion until soft
Add the garlic and cook briefly
Spread the onion and garlic mixture in a baking dish
Arrange the sliced vegetables in overlapping rows or circles over the onion mixture
Drizzle with olive oil
Season with salt, pepper, and herbs
Cover with foil and bake for about 30 minutes
Remove the foil and bake until the vegetables are tender
Serve warm