Low Carb Keto Crustless Pizza Casserole

The first time I made this, my skeptical husband asked where the actual pizza was. By the end of dinner, he was already planning when we could have it again. Something magical happens when pizza flavors melt together in a cheesy casserole form. This has become our go-to when those carb cravings hit but we want to stay on track.

Last winter, my sister came over during her first attempt at keto eating. She was missing pizza something fierce, so I whipped this up on a Tuesday night. Watching her face light up after that first bite reminded me why I love cooking so much. She texted me the next morning saying she had it for breakfast too.

Ingredients

• 1 lb ground Italian sausage: The spicy Italian variety adds that authentic pizza flavor, but mild works if you prefer less heat
• 20 slices pepperoni: Optional but highly recommended for those classic pizza vibes on top
• 1 cup sliced mushrooms: They shrink beautifully and soak up all those savory Italian flavors
• 1/2 cup diced green bell pepper: Adds a fresh crunch and that unmistakable pizza aroma
• 1/2 cup diced onion: Sweetens as it cooks, balancing the rich cheese and meat
• 2 cloves garlic, minced: Fresh garlic makes all the difference here, do not skip it
• 1 cup sugar-free pizza sauce: Check labels carefully, many marinara brands have hidden sugars
• 2 cups shredded mozzarella cheese: The stringy, melty cheese that makes everything better
• 1/2 cup shredded cheddar cheese: Adds extra sharpness and depth to the cheese layer
• 1/4 cup grated Parmesan cheese: Sprinkle this on top for that golden, salty finish
• 1 tsp dried Italian herbs: Oregano, basil, and thyme blend perfectly for that pizza seasoning flavor
• 1/2 tsp salt and black pepper: Adjust based on how salty your sausage and cheese are
• Red pepper flakes: Add these if you like a little heat in every bite

Instructions

Get your oven ready:

Preheat to 400°F and grab your favorite 9x9 baking dish. A little grease on the dish saves cleanup time later.

Brown the sausage:

Cook the ground Italian sausage in a large skillet over medium heat until no pink remains. Drain any excess fat if there is a lot pooling.

Add the veggies:

Toss in mushrooms, bell pepper, onion, and garlic. Sauté for 3-4 minutes until the vegetables soften and your kitchen smells amazing.

Build the flavor base:

Pour in the pizza sauce and sprinkle in Italian herbs, salt, and pepper. Let everything simmer together for 2-3 minutes.

Transfer to your baking dish:

Spread the meat and vegetable mixture evenly in your prepared baking dish.

Layer on the cheese:

Sprinkle mozzarella and cheddar across the top. Finish with Parmesan and arrange pepperoni slices if you are using them.

Bake until bubbly:

Bake uncovered for 20-25 minutes. You want the cheese melted and starting to turn golden in spots.

The hardest part:

Let it rest for 5 minutes before serving. This helps everything set so you get nice scoops instead of a runny mess.

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This recipe saved me during a particularly busy month when I was meal prepping for the first time. Coming home to something that just needed reheating felt like a luxury. Now whenever friends ask for easy keto dinner ideas, this is the first one I mention.

Make It Your Own

The beauty of this casserole is how customizable it is to what you have in the fridge or what your family prefers. I have made countless variations depending on what is on sale or what needs using up. The base formula stays the same but the personality changes.

Perfect Pairings

A crisp green salad with an acidic vinaigrette cuts through all that rich cheese beautifully. Sometimes I serve it with steamed broccoli or roasted zucchini on the side. If you are not strictly low carb, garlic bread is obviously never a mistake.

Storage and Reheating

This keeps beautifully in the refrigerator for up to five days and freezes well for those busy weeks ahead. I portion it into glass containers before freezing for easy grab and go lunches.

• Reheat individual portions in the microwave for 2-3 minutes
• For the best texture, reheat the whole dish covered at 350°F for 15-20 minutes
• Add a little extra cheese on top when reheating to refresh the melt factor

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Hope this becomes a weeknight staple in your house like it has in mine. There is something deeply satisfying about pizza flavors without the carb aftermath.

Recipe FAQs

→ Can I make this casserole dairy-free?

Yes, substitute dairy-free cheese alternatives for the mozzarella, cheddar, and Parmesan. Many brands melt well and provide similar texture. Ensure your sausage and marinara are also dairy-free.

→ How long does this keep in the refrigerator?

Store in an airtight container for up to 4-5 days. The flavors actually improve after a day. Reheat individual portions in the microwave or the entire dish in a 350°F oven until warmed through.

→ Can I freeze this crustless pizza casserole?

Absolutely. Bake completely, cool, then wrap tightly in foil and freeze for up to 3 months. Thaw overnight in the refrigerator before reheating. You can also freeze individual portions for quick meals.

→ What vegetables work best in this dish?

Mushrooms, bell peppers, and onions provide classic pizza flavor. Try adding black olives, roasted red peppers, spinach, or even zucchini. Avoid watery vegetables like fresh tomatoes that might make the casserole too loose.

→ Is this suitable for meal prep?

Perfect for meal prep. The entire casserole yields 4 generous servings and reheats beautifully. Portion into containers after cooling completely, and you'll have satisfying low-carb lunches or dinners ready throughout the week.

→ Can I use different meats?

Ground Italian sausage provides the most authentic pizza flavor, but ground beef, turkey, chicken, or plant-based crumbles all work well. Adjust seasonings slightly—beef might need extra Italian herbs, while turkey benefits from additional salt and pepper.