These cheesy keto stuffed peppers are a weeknight dinner that feels hearty and comforting without any of the carb-heavy fillers. Tender bell peppers hold a savory mix of seasoned beef, cauliflower rice, and marinara, all blanketed with bubbly mozzarella and Parmesan.

It all bakes in one dish, which means less cleanup and a meal that looks impressive straight from the oven.

What Makes These the Ones I Keep Coming Back To

The peppers soften just enough in the oven to stay bright and slightly sweet, which balances the rich, meaty filling. The cheese on top gets browned in spots and stretchy underneath, so every bite has a little pull.

Because the cauliflower rice soaks up the beef juices and sauce, you get that spoonable, saucy texture you would expect from rice, without any grain. It is filling, practical, and honestly, the kind of dinner that makes Monday feel a little easier.

Ingredients

4 medium bell peppers, any color: pick ones with flat bottoms so they sit steady.
1 lb ground beef: 80/20 works well; leaner beef can be a bit drier.
1 small yellow onion, diced
2 garlic cloves, minced
1 cup cauliflower rice: fresh or frozen, just squeeze out excess moisture if thawed.
1 cup sugar-free marinara sauce
1 cup shredded mozzarella
1/2 cup grated Parmesan
1 tsp Italian seasoning
1/2 tsp salt, plus more to taste
1/2 tsp black pepper
1 tbsp olive oil, plus a little for the peppers

Variations / Substitutions

Ground turkey or chicken: use a splash of olive oil while browning to keep it from drying out.
Dairy-free: swap both cheeses for a dairy-free mozzarella shred, and skip the Parmesan or use a nut-based alternative.
No marinara: a 1/2 cup of heavy cream with extra Italian seasoning makes a creamy, pink-sauce version.
Different vegetable base: riced broccoli works in place of cauliflower, but it will have a slightly earthier flavor.

For a similar low-carb comfort dish, try our Keto Cauliflower Casserole.

How to Make Cheesy Keto Stuffed Peppers

Step 1: Halve the Peppers

Preheat your oven to 400°F (200°C). Slice each bell pepper in half lengthwise, right through the stem. Remove the seeds and the white membranes, then brush the insides and outsides lightly with olive oil.

The peppers will soften during baking, so there is no need to parboil them first. Leaving them raw gives them enough structure to hold the filling without collapsing.

Step 2: Brown the Beef

Warm the 1 tbsp olive oil in a large skillet over medium-high heat. Add the diced onion and cook for 3 minutes, until it starts to turn translucent. Toss in the minced garlic and stir for 30 seconds, then crumble in the 1 lb ground beef. Break it apart with a spoon and cook for 6 to 8 minutes, until no pink remains.

You will see the beef separate into small, browned pieces, and the onion will soften further. If there is more than a tablespoon of fat left in the pan, drain it off so the filling does not become greasy.

Step 3: Stir in the Filling

Turn the heat down to medium and add the 1 cup cauliflower rice, the 1 cup marinara, the 1 tsp Italian seasoning, 1/2 tsp salt, and 1/2 tsp black pepper. Stir everything together and let it simmer for 3 to 4 minutes, just until the cauliflower rice is tender and the liquid has thickened into a cohesive, saucy mixture.

The filling should look moist and slightly loose but not soupy. It will set up a little more in the oven, so a bit of extra moisture is fine.

Step 4: Stuff the Peppers

Arrange the pepper halves cut side up in a baking dish that fits them snugly. Spoon the beef mixture into each half, filling them generously and mounding it slightly. You will use roughly 1/2 cup of filling per half.

Sprinkle the 1 cup mozzarella and the 1/2 cup Parmesan evenly over the tops. The cheese will melt into the crevices and form a crusty, golden layer as it bakes.

Step 5: Bake and Serve

Slide the dish into the oven and bake for 20 to 22 minutes. The peppers are ready when they feel tender when pierced with a fork and the cheese is bubbly with browned patches. Let them rest for 5 minutes before serving so the filling firms up and the peppers are easier to lift out. Serve them warm, scooping up any extra sauce from the bottom of the dish.

Tips for the Best Keto Stuffed Peppers

Look for flat-bottomed peppers.: They sit upright in the dish and keep the filling from spilling out during baking.
Squeeze thawed cauliflower rice dry.: If using frozen, nuke it first and press out the water with a clean towel so the filling stays thick.
Use a skillet that gives you room.: A 12-inch pan lets the beef brown instead of steam, which adds depth.
Broil for a minute at the end.: If you want the cheese extra golden and crisp, pop the peppers under the broiler for 1 to 2 minutes right after baking.

Keeping Leftovers Fresh

Refrigerate: Store cooled stuffed peppers in a sealed container for up to 4 days.
Reheating: Warm them in a 350°F oven for 10 to 12 minutes, or microwave in short bursts until heated through. The peppers will be softer but still taste great.
Freeze: Assemble the peppers without baking, wrap the dish tightly, and freeze for up to 2 months. Thaw overnight in the fridge, then bake as directed, adding about 5 minutes.

What to Serve with Keto Stuffed Peppers

A crisp green salad dressed with lemon and olive oil cuts through the richness of the beef and cheese. For something warm, sautéed zucchini with garlic comes together in a few minutes on the stovetop. A spoonful of full-fat sour cream on top adds a cool, tangy contrast right before you dig in.

Frequently Asked Questions

Can I use zucchini instead of bell peppers?

Yes, hollowed zucchini boats work well. Scoop out the seeds, reduce the baking time by 5 minutes, and keep an eye on them so they do not turn mushy.

How do I get the cheese on top really brown without overcooking the peppers?

Switch the oven to broil for the last 1 to 2 minutes of baking. Stand right there and watch it because the cheese can burn fast.

Can I make the filling ahead of time?

Absolutely. Brown the beef, stir in the remaining filling ingredients, and refrigerate it for up to 24 hours. When you are ready to eat, stuff and bake as usual, adding a few extra minutes since the filling will be cold.

Why did my peppers stay crunchy?

That means they needed more time in the oven. Pepper thickness varies, so if your fork meets resistance, bake them for another 5 to 8 minutes. A sheet of foil over the top can keep the cheese from getting too dark.