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Low-cal stuffed portobello pizzas are large mushroom caps baked until tender, then filled with marinara, spinach, tomatoes and mozzarella. Each one comes in around 180 calories and takes 37 minutes from start to finish.
I’ll be honest. I expected a sad diet swap. It isn’t one. The cap turns meaty and a little chewy, and the cheese does what pizza cheese does.
One step matters more than the rest. Portobellos hold a lot of water, and if you skip the pre-bake you get a soggy pool under the cheese. Ten minutes gill side down fixes it.
These sit right in a weeknight rotation. The filling mixes ahead, and kids like topping their own.
Why You’ll Love This Recipe
- About 180 calories and 13 g protein per stuffed cap
- Ready in 37 minutes using one sheet pan
- Filling and caps can be prepped a day ahead
- Kids can build their own with favorite toppings
Ingredient Notes
- portobello caps: Pick caps about 10 cm / 4 inches wide with edges that curl up slightly. Flat, wide caps spill their filling.
- part-skim mozzarella: Shred a low-moisture block yourself. Fresh mozzarella releases water and brings the puddle back.
- marinara sauce: Choose one with no added sugar and a thick texture. Thin sauce runs off the cap, so simmer it for a few minutes if yours looks loose.
- Parmesan: Adds salty depth for very few calories. Use a vegetarian-style hard cheese if you avoid animal rennet, or skip it.
Baked Stuffed Portobello Pizzas with Mozzarella and Basil
Ingredients
Method
- Heat the oven to 220 C / 425 F and line a 33 x 46 cm / 13 x 18 inch sheet pan with parchment. Wipe the caps with a damp paper towel, twist out the stems, and scrape out the gills with a spoon. Finely chop the stems and set them aside.
- Brush both sides of the caps with olive oil and season with the salt and black pepper. Set them gill side down on the pan and bake for 10 minutes, until the caps shrink slightly and liquid pools on the parchment.
- While the caps bake, stir the chopped stems, spinach, cherry tomatoes, garlic, oregano and red pepper flakes together in a bowl.
- Use tongs to flip the caps gill side up, blot them with a paper towel, and tip any liquid off the pan. Spoon 2 tbsp marinara into each cap, divide the filling among them, then top with the mozzarella and Parmesan.
- Bake for 10 to 12 minutes, until the cheese is bubbling with a few browned spots and a fork slides into the cap easily. Scatter the basil over the top and serve hot.
Notes
- Pre-bake the caps gill side down for 10 minutes, or the pizzas turn soggy.
- Blot the flipped caps with a paper towel and pour off pan liquid.
- Use 2 tbsp marinara per cap. More sauce makes the filling slide.
- Pull them when the cheese bubbles and a fork slides into the cap easily.
Tips for Success
- Scrape out the dark gills with a spoon, because they muddy the filling and release extra liquid as they cook.
- Bake the caps gill side down first, then blot the pooled liquid with a paper towel before adding any filling.
- Choose caps of similar size so all four finish at the same time and none dries out at the edges.
- Shred mozzarella from a low-moisture block instead of using fresh balls, which leave a watery layer on top of the sauce.
- Broil for the last 1 to 2 minutes if you want deeper browning, and watch closely because cheese goes from golden to burnt fast.
Variations
- Tuck 4 to 6 slices of turkey pepperoni under the cheese on each cap for a classic pepperoni pizza flavor.
- Swap the spinach for chopped roasted red pepper and sliced olives for a briny, Mediterranean-style version.
- Use a dairy-free mozzarella shred and skip the Parmesan to make these dairy free, then bake an extra 2 minutes.
Storage and Reheating
Leftover portobello pizzas keep for 3 days in an airtight container in the fridge. You’ll see a little liquid in the bottom of the container, so pour it off before reheating.
Reheat them on a sheet pan in a 190 C / 375 F oven for about 10 minutes, until the cheese is hot and bubbling again. Skip the microwave, which turns the caps rubbery.
For make-ahead, pre-bake and blot the caps, mix the filling, and store both separately in the fridge for up to 1 day. Assemble and bake as written, adding 2 to 3 minutes. I don’t freeze these, since thawed mushrooms turn soft and watery.
Serving Suggestions
Serve one cap per person as a light dinner with a big arugula salad dressed in lemon juice and a little olive oil. The peppery leaves cut through the cheese.
Hungrier crowd? Plate two caps each with a scoop of white beans or a bowl of minestrone. Roasted broccoli on the same sheet pan also works.
For kids, set out small bowls of toppings like diced peppers, olives and pepperoni, and let them build their own before the second bake.
FAQ
Why are my stuffed portobello pizzas watery?
Portobellos are about 90 percent water, and the caps release it as they bake. Pre-baking them gill side down for 10 minutes at 220 C / 425 F drains most of it. Then blot the caps and tip off the liquid on the pan before adding marinara and cheese. Skipping that step leaves a puddle under the pizza.
Can I use cremini or white button mushrooms instead of portobello caps?
You can, but it becomes a different dish. Use the largest button mushrooms you can find, about 5 cm / 2 inches wide, and remove the stems. Cut the pre-bake to about 6 minutes and the filled bake to about 8 minutes. They’re small, so plan on 3 to 4 per person.
Can I make stuffed portobello pizzas ahead or freeze them?
You can prep them a day ahead, but I wouldn’t freeze them. Pre-bake and blot the caps, mix the filling, and store both separately in the fridge. Assemble and bake straight from cold, adding 2 to 3 minutes. Frozen mushrooms turn watery and soft after thawing, which defeats the whole point.
What goes well with low-cal stuffed portobello pizzas?
An arugula salad with lemon and olive oil is my default. The peppery leaves cut through the cheese, and the plate stays light. Roasted broccoli or a cup of minestrone also work. For a bigger meal, serve two caps per person with a side of white beans.
Are stuffed portobello pizzas gluten free and keto-friendly?
They’re gluten free as written, since the mushroom replaces the crust. Each cap has about 9 g of carbs, so they fit most low-carb plans. Check your marinara label, because added sugar and starches creep in. For strict keto, use a no-sugar-added sauce and go easy on the tomatoes.
How is a portobello pizza different from regular stuffed mushrooms?
A portobello pizza is built like a personal pizza, with a marinara base, mozzarella on top and basil to finish. Regular stuffed mushrooms use small caps filled with breadcrumbs, cream cheese or sausage. The portobello is big enough to be a main, while stuffed mushrooms are usually an appetizer.
