Deep-Dish Baked Italian Sausage and Bell Pepper Casserole

By AislePrompt Test Kitchen · Reviewed by AislePrompt Editorial · Published 2026-05-29 · Updated 2026-05-29

A hearty, oven-baked Italian casserole combining spicy sausage, sweet bell peppers, and melted mozzarella, inspired by Chicago’s iconic deep-dish style but simplified for home cooking. This italian-inspired quick meals ready in about 55 minutes pairs Italian sausage, casing removed, red bell pepper, diced, green bell pepper, diced for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 480 calories and feeds 4, 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 lb Italian sausage, casing removed
• 1 cup red bell pepper, diced
• 1 cup green bell pepper, diced
• 1/2 cup yellow onion, diced
• 3 cloves garlic cloves, minced
• 14 oz can crushed tomatoes
• 2 tbsp tomato paste
• 1 tsp dried oregano
• 1 tsp dried basil
• 1 1/2 cups mozzarella cheese, shredded
• 1/4 cup grated Parmesan cheese
• 2 tbsp olive oil
• 1 tsp salt
• 1/2 tsp black pepper

Instructions

1. Step 1: Preheat your oven to 375°F. Heat 2 tbsp olive oil in a large skillet over medium heat and add 1 lb Italian sausage, breaking it up with a spoon. Cook for 7-8 minutes until browned and cooked through. Remove sausage to a bowl and set aside.
2. Step 2: In the same skillet, add 1/2 cup diced yellow onion and sauté for 3 minutes until translucent. Add 3 minced garlic cloves and continue cooking for 1 minute until fragrant.
3. Step 3: Add 1 cup diced red bell pepper and 1 cup diced green bell pepper to the skillet, cooking for 5 minutes until softened. Stir in 14 oz crushed tomatoes, 2 tbsp tomato paste, 1 tsp dried oregano, 1 tsp dried basil, 1 tsp salt, and 1/2 tsp black pepper. Simmer for 10 minutes until sauce thickens slightly.
4. Step 4: Return the cooked sausage to the skillet and stir to combine evenly with the sauce and vegetables. Transfer the mixture to a 9x9 inch baking dish.
5. Step 5: Sprinkle 1 1/2 cups shredded mozzarella cheese evenly over the top, then add 1/4 cup grated Parmesan cheese.
6. Step 6: Bake uncovered in the preheated oven for 20-25 minutes until cheese is melted, bubbly, and edges are slightly golden. Let rest for 5 minutes before serving.