Ratatouille-Style Baked Eggplant and Tomato Casserole

By Lauren Mitchell, Test Kitchen Director · Reviewed by AislePrompt Editorial · Published 2026-06-12 · Updated 2026-06-12

Layers of roasted eggplant, zucchini, bell peppers, and tomatoes baked with garlic and herbs for a vibrant, comforting Whole30 vegetable casserole. This mediterranean-inspired whole30 (whole30, vegetarian) ready in about 65 minutes pairs olive oil, minced garlic cloves, chopped fresh basil leaves for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 180 calories and feeds 6, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

Ingredients

• 1 large, sliced into 1/4-inch rounds eggplant
• 2 medium, sliced into 1/4-inch rounds zucchini
• 1 large, seeded and sliced into strips red bell pepper
• 1 large, seeded and sliced into strips yellow bell pepper
• 4 medium, sliced into 1/4-inch rounds tomatoes
• 4 tbsp olive oil
• 4, minced garlic cloves
• 1/4 cup, chopped fresh basil leaves
• 1 tbsp, chopped fresh thyme
• 1 tsp sea salt
• 1/2 tsp, freshly ground black pepper

Instructions

1. Step 1: Preheat oven to 400°F (200°C). Arrange 1 large sliced eggplant rounds on a rimmed baking sheet, brush both sides with 2 tbsp olive oil, and sprinkle with 1/2 tsp sea salt. Roast for 15 minutes until tender and lightly browned.
2. Step 2: In a large bowl, combine 2 medium sliced zucchinis, 1 large sliced red bell pepper, 1 large sliced yellow bell pepper, 4 minced garlic cloves, 2 tbsp olive oil, 1/2 tsp sea salt, 1/4 tsp black pepper, 1 tbsp chopped fresh thyme, and 1/4 cup chopped fresh basil. Toss until vegetables are well coated.
3. Step 3: In a 9x13-inch baking dish, layer the roasted eggplant slices, then half of the vegetable mixture, followed by 4 sliced tomatoes, and the remaining vegetable mixture. Drizzle with the remaining 2 tbsp olive oil and season with 1/4 tsp black pepper.
4. Step 4: Cover with foil and bake for 30 minutes, then remove foil and bake an additional 10 minutes until vegetables are tender and edges are caramelized. Let cool for 5 minutes before serving.