If you’re craving pizza but keeping things low-carb, these Portobello cap keto pizzas hit the spot. They’re quick, flavorful, and built on juicy mushroom caps that mimic a crispy, hearty crust. You get all the classic pizza vibes—melty cheese, zesty sauce, and your favorite toppings—without the carb crash.
Best of all, the whole thing comes together in about 15 minutes. Great for weeknights, lunch breaks, or whenever a pizza craving pops up.
What Makes This Recipe So Good
- Fast and fuss-free: About 15 minutes from start to finish, with minimal prep and cleanup.
- Low-carb comfort food: All the flavor of pizza, minus the dough and the blood sugar spike.
- Customizable: Build your own pies with whatever toppings you love—pepperoni, olives, peppers, pesto, you name it.
- Juicy yet sturdy “crust”: Portobello caps hold up well when pre-broiled, especially if you drain them and pat them dry.
- Great for meal prep: Make a batch and reheat quickly for a fast lunch or snack.
Shopping List
- 4 large Portobello mushroom caps (stems and gills trimmed)
- 2–3 tablespoons olive oil
- Salt and black pepper
- 1/2 cup sugar-free marinara or pizza sauce
- 1 cup shredded low-moisture mozzarella cheese
- 12–16 slices pepperoni (optional)
- 1/4 teaspoon garlic powder
- 1/2 teaspoon Italian seasoning or dried oregano
- 2 tablespoons grated Parmesan cheese
- Fresh basil or parsley for garnish (optional)
- Optional toppings: sliced black olives, sliced bell peppers, red onion, mushrooms, cooked sausage, cherry tomatoes, crushed red pepper
Instructions
- Prep the oven: Preheat the oven to 450°F (230°C). Line a baking sheet with foil and set a rack on top, if you have one.
The rack helps keep the caps from getting soggy.
Disclosure: As Amazon Associates, we earn from qualifying purchases at no extra cost to you. - Prepare the mushrooms: Wipe Portobello caps clean with a damp paper towel. Remove stems. Use a spoon to gently scrape out most of the gills, which can make things watery.
Pat the caps dry.
- Season and pre-broil: Brush both sides with olive oil. Sprinkle with salt, black pepper, and garlic powder. Place caps gill-side up on the rack or baking sheet.
Broil for 4–5 minutes, then carefully drain any liquid that pools inside the caps. Pat the insides dry.
- Sauce and cheese: Spoon about 2 tablespoons of marinara into each cap. Sprinkle Italian seasoning over the sauce.
Add mozzarella and a little Parmesan.
- Toppings: Add pepperoni or your preferred toppings. Keep toppings light so they heat through quickly and don’t weigh down the caps.
- Finish under heat: Return to the oven and bake for 5–7 minutes, or broil for 2–3 minutes until the cheese is melted and bubbly. Watch closely to avoid overcooking.
- Garnish and serve: Let the pizzas rest for 1–2 minutes.
Sprinkle fresh basil or parsley, and finish with a pinch of red pepper flakes if you like heat.
Storage Instructions
- Refrigerate: Store leftovers in an airtight container for up to 3 days. Place a paper towel beneath the pizzas to absorb moisture.
- Reheat: Warm in a hot skillet with a lid over medium heat for 3–5 minutes, or in a 375°F (190°C) oven for 6–8 minutes. Avoid microwaving if possible, as it can make them soggy.
- Freezing: Not recommended.
Mushrooms release water after thawing and can become rubbery.
Why This is Good for You
- Low in carbs, high in satisfaction: The mushroom base keeps net carbs low while delivering that pizza experience.
- Protein and fat balance: Cheese and toppings like pepperoni or sausage provide protein and fat to help keep you full.
- Micronutrient boost: Portobellos bring selenium, B vitamins, and potassium. Add colorful veggies for extra fiber and antioxidants.
- Better blood sugar stability: Skipping the crust helps reduce rapid glucose spikes, which is helpful for keto and low-carb eaters.
Common Mistakes to Avoid
- Skipping the pre-broil: If you don’t pre-broil and drain, your pizzas can end up watery. Always pre-cook the caps briefly and blot the moisture.
- Overloading toppings: Too many toppings weigh down the caps and prevent even heating.
Keep it to 2–3 toppings.
- Using fresh mozzarella: It has higher moisture and can make the pizzas soggy. Choose low-moisture mozzarella for best results.
- Not seasoning the caps: Mushrooms love salt and herbs. Season both before and after cooking for full flavor.
- Cooking too long: Mushrooms become rubbery if overcooked.
Watch the cheese—once it’s melted and bubbling, you’re done.
Alternatives
- White pizza: Skip marinara and use a thin layer of garlic-infused olive oil, a sprinkle of Parmesan, and mozzarella. Add spinach and mushrooms on top.
- Pesto base: Use basil pesto instead of marinara. Top with mozzarella, cherry tomatoes, and a few olives.
- Vegetarian supreme: Onions, peppers, olives, and spinach with mozzarella and a dusting of oregano.
- Dairy-free: Use a dairy-free mozzarella alternative and finish with a drizzle of olive oil and fresh herbs.
- Spicy: Add sliced jalapeños, spicy Italian sausage (pre-cooked), and crushed red pepper.
- Breakfast twist: Top with a thin layer of marinara, mozzarella, pre-cooked bacon crumbles, and finish with a dollop of ricotta or a fried egg on the side.
FAQ
Do I have to remove the gills from the mushroom caps?
Removing most of the gills helps reduce moisture and prevents a muddy flavor.
It takes a minute and makes a big difference, especially for texture.
Can I make these in an air fryer?
Yes. Preheat to 400°F (205°C). Air fry the seasoned caps for 3–4 minutes, drain, add toppings, and cook another 4–5 minutes until the cheese is melted.
What’s the best sauce for keto?
Choose a sugar-free marinara or pizza sauce with about 3–5 grams net carbs per serving.
You can also use pesto or crushed tomatoes seasoned with herbs and olive oil.
How do I keep the pizzas from getting soggy?
Pre-broil, drain, and pat the caps dry. Use low-moisture mozzarella and avoid heavy, watery toppings like fresh tomatoes unless sliced thin and patted dry.
Can I meal prep these?
Yes. Pre-broil and assemble the caps without cooking the cheese.
Store covered in the fridge for up to 24 hours. Bake or broil just before serving for best texture.
What toppings are most keto-friendly?
Pepperoni, cooked sausage, bacon, olives, mushrooms, spinach, peppers, and cheese are all great. Watch portions of onions and tomatoes if you’re tracking carbs closely.
Can I eat the stem?
Portobello stems are edible but fibrous.
Chop and sauté them for another dish, or finely dice and add to the topping mix after cooking to remove excess moisture.
Wrapping Up
These Portobello cap keto pizzas are a fast, flavorful fix for a pizza craving. With a quick pre-broil, smart toppings, and a hot oven, you’ll get melty, satisfying mini pies in about 15 minutes. Keep the ingredients on hand, and you’ll always have an easy low-carb meal ready to go.
Mix up the toppings, find your favorite combo, and enjoy pizza night any day of the week.
