Stuffed Pepper Casserole (Easy One-Pan Family Dinner)

Stuffed pepper casserole takes everything that makes the classic dinner special and gets rid of the fuss. No hollowing out individual peppers, no balancing them upright in a baking dish, and no eating around a half-cooked pepper wall. Everything goes into one pan and comes out bubbling, cheesy, and full of that familiar sweet pepper and beef flavor.

This is the version I make on busy weeknights when I want real comfort food without a pile of dishes. The rice cooks right in the pan with the beef and sauce, the peppers soften into something almost silky, and the whole thing is done in about an hour. It feeds six people and reheats beautifully the next day.

If you already love classic cheesy stuffed bell peppers, this casserole is going to be your go-to weeknight shortcut.

What Goes Into This Casserole

This is a short, practical ingredient list built on pantry staples and fresh peppers. The beef does the heavy lifting on flavor, so use a blend with some fat rather than extra-lean. Look for bell peppers that are firm and glossy, not soft or wrinkled.

• Ground beef. Provides the savory base. An 80/20 blend browns well and adds more flavor than extra-lean.
• Bell peppers. Use a mix of colors for sweetness, visual contrast, and that signature stuffed-pepper character.
• Yellow onion. Softens into the sauce and adds a natural sweetness as it cooks down.
• Garlic. Four cloves is the right amount. It rounds out the tomato base without taking over.
• Diced tomatoes. Leave the juices in. They cook into the rice and keep the casserole moist throughout the bake.
• Tomato sauce. Gives the filling a smooth, saucy body that coats every grain of rice and piece of beef.
• Beef broth. The liquid the dry rice absorbs as it bakes. Low-sodium gives you more control over the final seasoning.
• Long-grain white rice. Goes in completely dry and steams inside the covered casserole, coming out perfectly cooked and well-seasoned.
• Mozzarella and cheddar. Mozzarella melts stretchy and mild. Cheddar adds a sharper bite. Both go on for the final uncovered bake.

Building the Casserole Step by Step

1. Preheat the oven. Set it to 350°F (175°C) and spray a 9×13-inch baking dish with cooking spray.
2. Brown the beef. Cook the ground beef in a large skillet over medium-high heat, breaking it up as it goes, until no pink remains, about 7 to 8 minutes. Drain the excess fat.
3. Soften the vegetables. Add the diced onion and bell peppers to the same skillet and cook over medium heat for 4 to 5 minutes until they begin to soften. Stir in the minced garlic and cook 1 minute more.
4. Build the sauce. Add the diced tomatoes with their juice, tomato sauce, beef broth, Worcestershire sauce, Italian seasoning, and smoked paprika. Season with salt and pepper. Stir in the uncooked rice until evenly combined.
5. Transfer and bake covered. Pour the mixture into the prepared baking dish and spread it into an even layer. Cover tightly with aluminum foil and bake for 50 to 55 minutes, until the rice is tender and the liquid is mostly absorbed.
6. Add the cheese and finish. Remove the foil, scatter the mozzarella and cheddar evenly over the top, and bake uncovered for 10 to 12 more minutes until the cheese is melted and golden in spots. Rest 10 minutes before serving.

Why Uncooked Rice Works So Well

Adding dry rice directly to the casserole is the right move. As the dish bakes, the grains absorb the seasoned tomato broth from every direction. The rice carries flavor all the way through instead of just sitting in a pool of sauce.

The foil cover is what makes it work. It traps the steam so the rice cooks through without drying out. Press the foil flat against the rim of the dish before it goes into the oven. A loose seal lets steam escape and the rice on top can stay underdone while the bottom goes soft.

Use long-grain white rice only. Instant rice or parboiled rice absorb liquid at a different rate and will turn gummy before the filling finishes cooking. Brown rice works but needs about 20 extra minutes of covered bake time and an extra quarter cup of broth.

Pepper Colors and What They Bring

Red, orange, and yellow bell peppers are noticeably sweeter than green ones. They are simply further along in the ripening process with higher natural sugar content. A mix of red and green gives you sweetness balanced by a slight bitterness that keeps the tomato sauce from tasting flat.

Bell peppers also bring real nutritional weight. They are a strong source of vitamin C and antioxidants, particularly the red and orange varieties. Three medium peppers is the right amount for a 9×13 pan. More than that and the filling tilts toward a pepper stew rather than a casserole.

If you want heat, swap one green bell pepper for a poblano. It adds mild warmth without sharpness. A diced jalapeño stirred in with the garlic works if you want a real kick.

Swaps and Variations Worth Trying

Ground turkey is a one-to-one swap for the beef and keeps the dish lighter. Italian sausage removed from the casing adds richness and spice if you want something more indulgent. A mix of half beef and half sausage is a solid middle ground.

For a Mexican-leaning version, swap Italian seasoning for a teaspoon each of cumin and chili powder, use pepper jack instead of mozzarella, and stir in a can of drained black beans with the tomatoes. It tastes very close to a hearty Mexican casserole with ground beef and cheddar with a stuffed-pepper spin.

If you love the flavor of this dish in soup form, the hearty stuffed pepper soup uses the same profile and comes together even faster on cold nights.

Storing, Freezing, and Reheating

Let the casserole rest 10 minutes after it comes out of the oven. The sauce tightens slightly as it cools and portions hold together better when you scoop them.

Refrigerate leftovers in an airtight container for up to 5 days. Add a small splash of water or broth before microwaving to prevent the rice from drying out. For a full reheat from the fridge, cover with foil and warm at 325°F for about 20 minutes.

To freeze, cool the casserole completely, divide into portions, and store in airtight containers for up to 3 months. Thaw overnight in the refrigerator before reheating. The rice texture holds up well and the cheese layer comes back nicely when warmed covered in the oven.

FAQs

Can I use uncooked rice directly in the casserole?

Yes, and it works better than adding pre-cooked rice. The uncooked grains absorb the seasoned tomato broth as the casserole bakes, so every grain is flavored all the way through. Stick to long-grain white rice and avoid instant or parboiled varieties, which turn mushy. Make sure the foil is sealed tight so the steam stays in and cooks the rice evenly.

Can I freeze stuffed pepper casserole?

Yes. Let it cool completely, then portion into airtight freezer containers or wrap the whole dish tightly with plastic wrap and foil. It keeps well for up to 3 months. Thaw overnight in the refrigerator before reheating covered in a 325°F oven until heated through, about 25 to 30 minutes.

What can I substitute for ground beef?

Ground turkey or ground chicken work well and keep the dish lighter. Italian sausage removed from the casing adds richer, spiced flavor. Whatever you choose, brown and drain it thoroughly before adding the vegetables. The cook time stays the same.

Which bell pepper colors work best?

A mix of red, yellow, and green gives the best balance of sweetness and visual appeal. Red and yellow peppers are sweeter and softer after baking. Green peppers stay slightly firmer and have a mild bitterness that keeps the tomato sauce from tasting one-note. All one color works fine too.

How do I know when the casserole is fully cooked?

The rice should be tender all the way through and most of the liquid absorbed. Press a fork into the center to check. If the rice still feels firm, re-cover with foil and bake another 10 minutes before checking again. Make sure the ground beef was cooked to 160°F before it went into the dish, per USDA safe cooking temperature guidelines.

Can I make stuffed pepper casserole in a slow cooker?

Yes. Brown the beef on the stovetop first, then combine everything in the slow cooker and cook on LOW for 4 to 5 hours or HIGH for 2 to 3 hours. Add the cheese in the last 20 minutes with the lid on. The easy stuffed pepper casserole with beef and rice on this site also adapts well to this method.

How long do leftovers keep in the refrigerator?

Stored in an airtight container, leftovers stay good for 4 to 5 days in the fridge. Reheat individual portions in the microwave with a small splash of water or broth to prevent the rice from drying out. For a full reheat, cover the dish with foil and warm at 325°F for about 20 minutes.

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