Supreme stuffed portobello mushroom pizzas are a delicious way to enjoy all the flavors of a supreme pizza in a healthier way. A mixture of pizza sauce, Italian sausage, pepperoni, peppers, olives, and more are covered in fresh mozzarella in these easy stuffed portobello mushrooms.
Preheat oven to 400°F. Wipe eat portobello mushroom cap with a damp paper towel to clean them off. Remove the stems and gently scrape out the gills.
Place an oven-safe wire rack on a rimmed baking sheet. Spray it generously with cooking spray.
Season the front and back of each mushroom cap with salt, pepper, and garlic powder. Place them on the wire rack and bake for 10 minutes.
Blot any excess moisture that you can from the mushrooms and flip them over. Spoon approximately 1 1/2 tablespoons of marinara sauce into the well of each mushroom cap. Evenly scatter sausage, pepperoni, onion, olives, and peppers over each mushroom, and top with sliced mozzarella.
Bake for 10 minutes, or until heated throughout and the cheese is melted. If desired, pop them under the broiler at the end of the cook time to brown the cheese. Garnish with fresh basil and serve immediately.