Best Stuffed Pepper Casserole

by Sophia

There’s something so comforting about digging into a warm, cheesy casserole straight from the oven—especially one that brings all the flavors of classic stuffed peppers into one easy-to-make dish. This Best Stuffed Pepper Casserole has become a go-to weeknight meal in our house, and I just know it’ll be a hit in yours too.

If you’re anything like me, sometimes the idea of stuffing individual peppers feels like a lot of extra work—especially on a busy night. That’s exactly why this casserole version is so perfect. It captures everything we love about traditional stuffed peppers—savory ground beef, tender rice, sweet bell peppers, and rich tomato sauce—all baked together under a bubbly layer of cheese. And let’s be honest: who can resist melted mozzarella?

I’ve made this dish more times than I can count, and it never fails to please everyone at the table. Even my pickiest eater happily goes back for seconds (and sometimes thirds!). It’s hearty, flavorful, and the kind of recipe that fills the kitchen with those cozy, “home-cooked meal” vibes that just make you want to gather around the table and dig in.

So let’s get into it! I’ll walk you through how to make this dish step by step—and trust me, it’s a breeze.

Ingredients You’ll Need

4 bell peppers (any color), diced

1 pound ground beef
1 small onion, finely chopped
2 garlic cloves, minced

1 cup cooked rice
1 can (14.5 oz) diced tomatoes, undrained
1 can (8 oz) tomato sauce

1 teaspoon Italian seasoning
Salt and freshly ground black pepper, to taste
1 cup shredded mozzarella cheese

¼ cup grated Parmesan cheese
2 tablespoons chopped fresh parsley (optional)

STEP 1: PREP YOUR OVEN AND DISH

Start by preheating your oven to 350°F. While it’s heating, lightly grease a 9×13-inch baking dish and set it aside. This will be your casserole’s cozy home while it bakes.

STEP 2: BROWN THE BEEF

In a large skillet over medium heat, add your ground beef. Cook it until it’s no longer pink, using a wooden spoon or spatula to break it into crumbles. Once it’s fully browned, go ahead and drain off any excess fat so your casserole doesn’t get greasy.

STEP 3: ADD AROMATICS

Next, stir in your chopped onion and minced garlic. Keep cooking for a few more minutes, just until the onion becomes translucent and fragrant. This step really builds that savory base flavor we’re going for.

STEP 4: ADD THE BELL PEPPERS

Now, toss in your diced bell peppers. Any color works here—red, yellow, green, or a mix. Let them cook for about 2–3 minutes, just until they start to soften up a bit. They’ll finish cooking in the oven, so you don’t need to overdo it here.

STEP 5: COMBINE WITH RICE AND SAUCE

Stir in your cooked rice, the entire can of diced tomatoes (juice included), and the tomato sauce. Sprinkle in the Italian seasoning, then season with salt and pepper to your taste. Let everything simmer together for about 5 minutes, stirring occasionally. This gives the flavors a chance to meld and the sauce to thicken slightly.

Alright, let’s pick up right where we left off! At this point, you’ve got a hearty, savory skillet mixture of ground beef, bell peppers, rice, and tomatoes—all simmered into a beautifully thickened filling. Now comes the fun part: turning that delicious mixture into a baked, bubbly casserole that’s topped with just the right amount of melty cheese.

This is where the magic really happens. As everything bakes together, the flavors continue to deepen and the cheese on top turns into a golden, gooey layer that pulls the whole dish together. Whether you’re feeding a hungry family or meal-prepping for the week, this is the kind of dinner that never disappoints.

Let’s dive into the next steps and get this casserole in the oven!

STEP 6: TRANSFER TO THE BAKING DISH

Carefully pour or spoon your beef and rice mixture into the greased 9×13-inch baking dish. Use a spatula or the back of your spoon to spread it out evenly. You want every bite to have a good balance of meat, rice, and veggies.

STEP 7: ADD THE CHEESE TOPPING

Time to layer on the goodness! Sprinkle 1 cup of shredded mozzarella cheese evenly over the top of the casserole. Then follow that with ¼ cup of grated Parmesan cheese for a little salty, nutty flavor that balances out the tomato base beautifully.

This cheesy topping is what transforms the dish from a skillet dinner into a true casserole. And yes, it gets golden and bubbly in the oven—just wait until you smell it baking!

STEP 8: BAKE UNTIL MELTY AND BUBBLY

Place the dish into your preheated 350°F oven and bake for 20 to 25 minutes. You’re looking for the cheese to be completely melted, lightly golden, and bubbling around the edges. That’s your cue that everything is perfectly heated through and ready to serve.

If you like a little extra browning on top (like I do), you can pop it under the broiler for 1–2 minutes right at the end. Just be sure to watch it closely—it can go from golden to burned pretty fast!

STEP 9: LET IT REST, THEN GARNISH

Once it comes out of the oven, give your casserole a few minutes to rest—about 5 minutes will do. This helps the casserole set up a bit and makes it easier to scoop out those satisfying servings.

For a little extra color and a pop of freshness, sprinkle chopped fresh parsley over the top right before serving. It’s optional, but it really brightens things up and adds a nice finishing touch.

TIPS AND VARIATIONS TO TRY

Here’s where you can have a little fun with this recipe and make it your own. Below are some of my favorite tweaks that keep things interesting from week to week:

Add more veggies: Want to sneak in a little more produce? Stir in a cup of chopped zucchini or sliced mushrooms when you add the bell peppers. They blend right in and add extra nutrition and flavor.
Change up the protein: This casserole works just as well with ground turkey, ground chicken, or even Italian sausage. I love using mild sausage when I want to give the dish a little extra punch.

Make it spicier: Like a little heat? Add a pinch of crushed red pepper flakes or a chopped jalapeño when cooking the beef and onions. It gives the casserole a fun kick without overwhelming the other flavors.
Use different cheeses: Mozzarella is a classic here, but don’t be afraid to mix it up. Try cheddar, Monterey Jack, or even a little pepper jack if you’re feeling bold.
Make it ahead: If you’re planning a busy night, this dish is a lifesaver. You can assemble the entire casserole up to 24 hours in advance (just leave off the cheese), cover it with foil, and store it in the fridge. When you’re ready to bake, sprinkle on the cheese and pop it in the oven!

You’ve made it to the final part of this cozy casserole journey, and if you’re anything like me, you’re already thinking about seconds. Before we wrap things up, I want to answer a few common questions that tend to come up when making this Best Stuffed Pepper Casserole—especially if it’s your first time trying it.

These tips and answers should help troubleshoot any little issues and give you the confidence to tweak or adapt the recipe as needed. After that, I’ll leave you with a few closing thoughts and an invitation to make this dish your own!

FREQUENTLY ASKED QUESTIONS

Can I use uncooked rice instead of cooked rice?
Not for this recipe. The rice should be fully cooked before you add it to the skillet. Using uncooked rice would throw off the liquid balance and may leave you with undercooked grains.

What’s the best way to store leftovers?
Store any leftovers in an airtight container in the refrigerator for up to 3 days. Reheat individual portions in the microwave or warm the whole dish in the oven at 325°F until heated through.

Can I freeze this casserole?
Absolutely! Assemble the casserole (without baking), let it cool completely, then wrap it tightly with foil and freeze for up to 2 months. When you’re ready to eat, thaw it overnight in the fridge, add the cheese on top, and bake until warmed through.

What can I use instead of ground beef?
Feel free to swap in ground turkey, chicken, or Italian sausage—all work great and bring different flavors. If you want a vegetarian version, use plant-based ground meat or lentils.

Can I make this casserole low-carb?
Yes! Replace the cooked rice with cauliflower rice for a lower-carb version. You may want to reduce the tomato liquid slightly, since cauliflower rice doesn’t absorb as much moisture as regular rice.

Do I have to use mozzarella and Parmesan?
Not at all! You can mix and match cheeses based on what you like or have on hand. Cheddar, Monterey Jack, or even a sprinkle of feta can add fun new twists to the flavor.

Why is my casserole watery?
If your casserole turns out a bit watery, it might be from excess moisture in the tomatoes or bell peppers. To fix this next time, you can drain a little liquid from the canned tomatoes before adding, or simmer the filling a bit longer before transferring it to the baking dish.

FINAL THOUGHTS

There’s just something about this stuffed pepper casserole that makes it feel like a warm hug in food form. It’s hearty, comforting, and full of flavor—but still simple enough to whip up on a busy weeknight without breaking a sweat.

I’ve made this recipe for family dinners, casual potlucks, and even meal prep Sundays, and it always delivers. The best part is how adaptable it is—you can mix up the protein, toss in extra veggies, or play around with different cheeses, and it still turns out absolutely delicious every single time.

If you give this casserole a try, I’d love to hear how it goes! Did you stick to the classic version or add your own twist? Let me know in the comments, and feel free to share your favorite variations. Recipes like this are meant to be shared, adapted, and passed along.