This Italian Sausage & Pepper Casserole is a hearty, flavor-packed dish that brings the bold taste of savory Italian sausage together with sweet, tender bell peppers in a comforting, cheesy bake. Perfect for weeknight dinners or casual gatherings, this casserole is easy to prepare, satisfying, and loaded with vibrant colors and rich, mouthwatering flavors that everyone will love.
Servings: 6
Ingredients
Main Ingredients
- 1 lb 450g Italian sausage (mild or spicy, casings removed)
- 2 red bell peppers thinly sliced
- 2 yellow bell peppers thinly sliced
- 1 medium onion thinly sliced
- 3 cloves garlic minced
- 1 can 14.5 oz / 410g diced tomatoes
- 1 tbsp tomato paste
- 1 tsp dried oregano
- 1 tsp dried basil
- ½ tsp crushed red pepper flakes optional, for heat
- Salt and black pepper to taste
- 2 tbsp olive oil
Optional Topping
- ½ cup shredded mozzarella or Parmesan cheese
Instructions
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Preheat & Prep
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Preheat your oven to 375°F (190°C).
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Lightly grease a 9×13-inch casserole dish with olive oil or non-stick spray.
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Cook the Sausage
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In a large skillet over medium heat, add 1 tbsp olive oil.
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Cook Italian sausage until browned and fully cooked, breaking into chunks with a spatula (about 5–7 minutes).
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Remove sausage and set aside.
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Sauté the Vegetables
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In the same skillet, add remaining 1 tbsp olive oil.
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Sauté onion, bell peppers, and garlic until tender and fragrant (5–6 minutes).
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Season with salt, pepper, oregano, basil, and optional red pepper flakes.
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Add Tomatoes
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Stir in diced tomatoes and tomato paste.
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Simmer for 3–4 minutes to allow flavors to blend.
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Assemble the Casserole
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Transfer the cooked sausage to the casserole dish.
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Pour the sautéed pepper and tomato mixture on top.
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Gently stir to combine evenly.
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Sprinkle cheese on top if desired.
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Bake
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Cover the dish with foil and bake for 20 minutes.
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Remove foil and bake an additional 10–15 minutes until the top is golden and bubbly.
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Serve
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Let the casserole rest 5 minutes before serving.
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Serve warm with crusty bread, rice, or pasta.

