Offline Wikipedia-Inspired Layered Vegetable Casserole

By Lauren Mitchell, Test Kitchen Director · Reviewed by AislePrompt Editorial · Published 2026-06-27 · Updated 2026-06-27

A comforting layered vegetable casserole that combines colorful seasonal produce with a creamy béchamel sauce, perfect for a wholesome family dinner. This mediterranean-inspired vegetarian (vegetarian) ready in about 70 minutes pairs medium (about 1 lb) eggplant, medium (about 1 lb) zucchini, large red bell pepper for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 280 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 medium (about 1 lb) eggplant
• 2 medium (about 1 lb) zucchini
• 1 large red bell pepper
• 1 large yellow bell pepper
• 4 tbsp olive oil
• 1 medium, finely chopped onion
• 3, minced garlic cloves
• 3 tbsp all-purpose flour
• 2 cups whole milk milk
• 1/2 cup grated Parmesan cheese
• 1 tsp salt
• 1/2 tsp black pepper
• 1 tsp fresh thyme leaves
• 1/4 cup, chopped fresh basil leaves
• 1/4 cup breadcrumbs

Instructions

1. Step 1: Preheat oven to 375°F. Slice 1 medium eggplant and 2 medium zucchinis into 1/4-inch thick rounds. Halve, seed, and slice 1 large red bell pepper and 1 large yellow bell pepper into 1/2-inch strips. Toss all vegetables with 2 tbsp olive oil and 1/2 tsp salt.
2. Step 2: Arrange the vegetables on a baking sheet in a single layer and roast in the oven for 20 minutes until tender and edges lightly caramelized.
3. Step 3: While vegetables roast, heat 2 tbsp olive oil in a medium saucepan over medium heat. Add 1 medium finely chopped onion and 3 minced garlic cloves, sauté for 5 minutes until soft and fragrant.
4. Step 4: Sprinkle 3 tbsp all-purpose flour over the onion and garlic mixture, stirring constantly for 2 minutes to cook the flour.
5. Step 5: Gradually whisk in 2 cups whole milk, continuing to stir until the sauce thickens and coats the back of a spoon, about 5-7 minutes. Remove from heat and stir in 1/2 cup grated Parmesan cheese, 1 tsp salt, 1/2 tsp black pepper, and 1 tsp fresh thyme leaves.
6. Step 6: In a baking dish, layer half the roasted vegetables, pour half the béchamel sauce over them, then sprinkle 1/8 cup chopped fresh basil leaves. Repeat with the remaining vegetables and sauce, finishing with 1/4 cup breadcrumbs evenly spread on top.
7. Step 7: Bake uncovered at 375°F for 25 minutes until the top is golden and bubbling. Let rest 10 minutes before serving.