Easy Low Carb Keto Crustless Pizza

The first time I made this pizza casserole, my husband actually asked if I'd ordered delivery. The smell bubbling through the house was identical to our local pizza joint, minus the carb-induced guilt. I've since learned that the secret really is in the Italian sausage seasoning that infuses every single layer with that familiar pizzeria aroma we all crave on Friday nights.

Last winter, when my sister started her keto journey, she complained constantly about missing pizza nights at our family gatherings. I threw together this casserole on a whim, using whatever ground meat and cheese I had in the fridge. She took one bite and literally got teary, saying it was the first time in months she didn't feel deprived while everyone else ate regular pizza.

Ingredients

• 1 lb ground Italian sausage: The fennel and herbs in pre-seasoned sausage create that authentic pizza flavor without having to measure a dozen spices
• 20 slices pepperoni: These get crispy on top and add that classic pepperoni grease that flavors everything underneath
• 1 cup sliced mushrooms: They shrink down and concentrate their umami, almost mimicking the texture of a thick crust layer
• 1/2 cup diced green bell pepper: Fresh crunch that cuts through all the rich cheese and meat
• 1/2 cup diced onion: Sweetens as it cooks, balancing the salty sausage and sharp cheeses
• 2 cloves garlic, minced: Don't skip this even if you're tired after work, it makes the kitchen smell incredible
• 1 cup sugar-free pizza sauce: Look for brands with no added sugar, or regular marinara works perfectly too
• 2 cups shredded mozzarella cheese: The melt factor you want for that cheese pull in every spoonful
• 1/2 cup shredded cheddar cheese: Adds a sharpness that cuts through the mild mozzarella
• 1/4 cup grated Parmesan cheese: Sprinkle this on last for a salty, golden crust on top
• 1 tsp dried Italian herbs: Extra insurance that pizza flavor comes through loud and clear
• 1/2 tsp salt and 1/2 tsp black pepper: Adjust to taste, but the sausage and cheese already bring a lot of saltiness
• Red pepper flakes: If you like a little heat like we do, don't be shy with this

Instructions

Get your oven ready:

Preheat to 400°F so it's fully hot by the time your meat mixture is ready

Brown the sausage:

Cook the ground Italian sausage in a large skillet over medium heat until no pink remains, then drain any excess fat

Add the vegetables:

Toss in the mushrooms, bell pepper, onion, and garlic, sautéing for 3-4 minutes until softened and fragrant

Build the flavor base:

Stir in the pizza sauce, Italian herbs, salt, and black pepper, letting everything simmer together for 2-3 minutes

Transfer to baking dish:

Pour the mixture into a greased 9x9-inch baking dish, spreading it evenly

Layer on the cheese:

Sprinkle mozzarella and cheddar across the top, then add Parmesan and arrange pepperoni slices if you're using them

Bake until bubbly:

Cook uncovered for 20-25 minutes until the cheese is melted and starting to turn golden in spots

Let it rest:

Wait 5 minutes before serving so everything sets and you get neat portions instead of a sloppy scoop

Save

This became my go-to meal when I'm hosting friends who don't eat low carb because it satisfies everyone without drawing attention to being diet food. Something about breaking out the casserole dish makes people feel taken care of in a way that individual portions never quite achieve.

Making It Your Own

The beauty here is that you can swap ground turkey or beef for the sausage depending on what your family prefers. Sometimes I'll throw in black olives or spinach if that's what needs using up in the crisper drawer, and nobody has complained yet about extra vegetables hiding in all that cheese.

Meal Prep Magic

I've started doubling this recipe on Sundays and portioning it into individual containers for the week's lunches. The flavors actually get better after a day or two in the refrigerator, giving all those herbs and spices time to really meld together in a way that fresh baking can't quite achieve.

Serving Suggestions

A crisp green salad with an acidic vinaigrette cuts through the richness of all that cheese perfectly. I also like to serve it with steamed broccoli or roasted cauliflower on the side, which feels appropriately Italian while keeping everything low carb and satisfying.

• Crushed red pepper on the table lets everyone adjust their own heat level
• Extra Parmesan for sprinkling at the table never hurts
• Garlic powder mixed into your salad dressing ties everything together

Save

There's something deeply satisfying about watching people scrape their plates clean without realizing they just ate something that fits perfectly into a low carb lifestyle. Enjoy those pizza night vibes.

Recipe FAQs

→ Can I freeze this casserole?

Yes, this casserole freezes well for up to 3 months. Allow it to cool completely, then wrap tightly in foil and freeze. Thaw overnight in the refrigerator before reheating at 350°F until warmed through.

→ What other proteins work in this dish?

Ground beef, turkey, or plant-based crumbles make excellent substitutes for Italian sausage. Each option maintains the hearty texture while offering different flavor profiles. Season additional proteins with Italian herbs to keep the classic taste.

→ How do I make it spicier?

Add hot Italian sausage instead of mild, increase the red pepper flakes to 1 teaspoon, or mix in some crushed red pepper with the sauce layer. You can also use spicy pepperoni or add diced jalapeños with the vegetables.

→ Can I prepare this ahead of time?

Assemble the entire casserole up to 24 hours in advance, cover tightly, and refrigerate. When ready to bake, add 5-10 minutes to the cooking time since it will be cold. The flavors actually develop more depth when given time to meld.

→ What vegetables can I add?

Spinach, black olives, roasted red peppers, or zucchini work beautifully. Sauté hearty vegetables like zucchini with the peppers and onions, but add delicate greens like spinach just before baking to prevent wilting.

→ Is the sugar-free sauce necessary?

For strict keto or low-carb diets, yes—regular marinara can contain 6-8 grams of sugar per serving. Look for brands with no added sugar or make your own with crushed tomatoes, garlic, and Italian herbs.