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Sausage Portobello Pizza on a white plate with basil leaves

Grilled Sausage Portobello Mushroom Pizza

Valentina K. Wein
This Portobello Mushroom Pizza is impossible not to love! It's absolutely scrumptious and also happens to be gluten-free and low-carb. This is obviously what you have to cook next and it will be a huge hit!
5 from 10 votes
Prep Time 15 mins
Cook Time 35 mins
Total Time 50 mins
Course Appetizer, Dinner
Cuisine Italian
Servings 4
Calories 292 kcal


  • 3 cups yellow onion, thinly sliced (about 1 large onion)
  • 4 tablespoons unsalted butter
  • 4 large portobello mushrooms (approximately 5-inch diameter)
  • olive oil for the grill
  • about 2 dozen basil leaves, washed and dried
  • 3/4 cup mozzarella cheese, grated
  • 3 small tomatoes, washed and dried, thinly sliced (you will need approximately 12 slices)
  • 1 (4-ounce) raw sweet Italian sausage
  • salt and freshly ground black pepper


  • Add the butter to a large pot and turn the heat to low. Once the butter has melted completely, use a spoon to remove the milk solids (white foam) from the surface and discard. Then turn the heat to medium-high and add the onions. Stirring often, sauté until they're a deep golden color and very soft. This should take about 25 minutes. About halfway through the cooking time, reduce the heat to medium-low. Season to taste with salt and pepper. (Here's How to Season to Taste.) Remove the onions from the pot and add them to a small bowl. What was 3 cups will now be about 1/2 cup. Set aside.
  • Squeeze the sausage out of its casing into the same pot, break it apart and sauté until it's cooked through. Set aside.
  • Preheat the oven to 375°F, and line a baking sheet with foil. Set aside.
  • Use a damp paper towel or kitchen towel to wipe the mushroom caps clean. Remove the stems from the mushrooms by wiggling them gently. Then use a small spoon to scrape the gills off the underside of the mushrooms.
  • Over a high flame, preheat a stove-top grill. (See notes!) On a large plate, drizzle the mushrooms with olive oil on both sides and season generously with salt and pepper. Place them on the preheated grill — if you don’t hear a sizzle, take them off until it’s hot enough that you do. They will not caramelize properly unless it's hot enough. Grill them until they're nicely browned and tender, 3 or 4 minutes per side. When they're done, place them on the foiled covered baking sheet, round side down.
  • Place enough basil leaves on each mushroom to cover the surface. Divide the cheese evenly among them, sprinkling it directly on top of the basil. Then dividing them equally, add the caramelized onions, followed by the tomato slices and sausage.
  • Place the "pizzas" in the preheated 375°F oven and bake until the the cheese is completely melted, about 5 minutes.
  • Finely chop the remaining basil and sprinkle in on top of each one and serve.


If you don't have a stove-top grill, you can sauté the mushrooms in a skillet following the same instructions. (A cast iron skillet is ideal.)
Keywords gluten-free pizza recipes, appetizers for sharing
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