Prep the vegetables – Wash and slice zucchini and eggplant. Chop peppers, tomatoes, and onions. Mince garlic.
Sauté the onions and garlic – Heat 1 tablespoon olive oil in a large pan. Cook onions until soft, add garlic, and stir for 1 minute.
Cook vegetables separately – In the same pan, add another tablespoon olive oil and sauté zucchini until slightly tender. Remove and set aside. Repeat with eggplant and peppers.
Make the tomato base – Add tomatoes to the pan with remaining olive oil, thyme, and rosemary. Cook for 10 minutes until the sauce thickens.
Combine and simmer – Return all vegetables to the pan. Mix gently, season with salt and pepper. Cover and simmer for 20–25 minutes over low heat.
Finish with basil – Stir in fresh basil before serving.