This oven-baked 6-ingredient stuffed pepper casserole captures all the cozy flavors of classic stuffed peppers without the fuss of hollowing and par-cooking the peppers. Instead, you layer seasoned ground beef in a baking dish, then spread canned tomato sauce and four simple mix-ins over the top for a weeknight-friendly comfort meal. It’s loosely inspired by Midwestern casserole culture—think potlucks and Sunday suppers—where convenience ingredients like canned tomato sauce and pre-shredded cheese are embraced, but the flavors are still big, warm, and satisfying.
Serve this stuffed pepper casserole with a crisp green salad dressed in a simple vinaigrette to balance the richness, and add warm crusty bread or garlic toast to soak up the extra tomato sauce. A side of steamed green beans or roasted broccoli works nicely if you want more vegetables on the plate. For drinks, a light red wine, a lager, or even sparkling water with lemon keeps the meal feeling relaxed and homey.
Oven-Baked 6-Ingredient Stuffed Pepper CasseroleServings: 6
Ingredients
1 1/2 pounds ground beef (80–90% lean)
2 cups cooked white rice (or leftover rice, fluffed)
2 large bell peppers, diced (any color)
2 cups shredded mozzarella cheese (about 8 ounces)
1 teaspoon kosher salt (plus more to taste)
1/2 teaspoon freshly ground black pepper
1 can (24–26 ounces) plain tomato sauce
Directions
Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish with a bit of oil or nonstick spray so the casserole releases easily after baking.
Spread the raw ground beef evenly across the bottom of the baking dish, pressing it gently into an even layer with clean hands or the back of a spoon. It should cover the base from edge to edge, like a thin meatloaf layer.
Season the ground beef layer evenly with the kosher salt and black pepper. This base seasoning is important because the beef will cook in place under the sauce and toppings.
In a medium bowl, combine the cooked rice and diced bell peppers, tossing them together so the peppers are evenly distributed. This mixture mimics the filling of classic stuffed peppers but will bake right on top of the beef.
Sprinkle the rice and pepper mixture evenly over the seasoned ground beef, covering it completely. Gently press it down so it settles into an even layer without compacting it too tightly.
Open the canned tomato sauce and pour it over the rice and pepper layer. Using the back of a spoon or a spatula, spread the sauce all the way to the edges of the dish, as in the photo-style process shot: a close, high-angle view of hands smoothing store-bought sauce over the ground beef base and toppings. You want everything coated with a generous blanket of sauce.
Cover the baking dish tightly with aluminum foil. Bake in the preheated oven for 35–40 minutes, or until the beef is cooked through and the peppers are tender. If you have an instant-read thermometer, the center should reach at least 160°F (71°C).
Carefully remove the foil (watch for hot steam). Sprinkle the shredded mozzarella cheese evenly over the hot casserole, making sure to cover as much surface as possible for a melty top.
Return the uncovered casserole to the oven and bake for another 10–12 minutes, until the cheese is melted and bubbling and the edges of the sauce are just starting to caramelize.
Let the casserole rest for 10 minutes before serving. This brief rest allows the layers to settle and makes it easier to cut neat squares. Slice and serve warm, scooping down through the cheesy top into the saucy beef, rice, and pepper layers.
Variations & Tips
You can easily adapt this casserole to suit your pantry and preferences while preserving the core method of spreading canned tomato sauce and four simple ingredients over ground beef. For a slightly lighter version, substitute ground turkey or a 50/50 mix of ground beef and ground turkey, but be sure to keep the internal temperature at or above 165°F (74°C) for poultry. If you prefer a bit of heat, add a pinch of red pepper flakes or a diced jalapeño to the rice and pepper mixture. For a more Mediterranean profile, swap mozzarella for shredded provolone or an Italian blend and stir 1 teaspoon of dried Italian seasoning into the tomato sauce before spreading it. Brown rice or quinoa can replace the white rice; just make sure they are fully cooked before layering, as the oven time is designed to heat and meld, not fully cook raw grains. To make it more vegetable-forward, increase the bell peppers to three and add a cup of chopped zucchini or mushrooms to the rice mixture. Food safety tips: Always wash your hands thoroughly before and after handling raw ground beef, and sanitize any surfaces or utensils that come into contact with it. Keep the raw meat separate from vegetables until they meet in the baking dish. Bake the casserole until the center reaches at least 160°F (71°C) for beef, and refrigerate leftovers within 2 hours in shallow containers. Reheat leftovers to at least 165°F (74°C) before eating.
