Stuffed Portabella Mushroom Recipe

Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper or lightly grease a rimmed baking sheet.

Clean the portabella mushrooms: wipe caps with a damp paper towel. Remove and reserve stems and scrape out gills using a spoon (reserve gill/stem mixture for the filling).

Brush both sides of the mushroom caps with 2 tablespoons olive oil and season the underside and top lightly with 1 teaspoon salt and 1/2 teaspoon black pepper. Place caps gill-side up on the prepared baking sheet.

Prepare and cook filling base

Heat a large skillet over medium heat. Add 2 tablespoons butter and 1 tablespoon olive oil. When butter foams, add the diced onion and cook for 4–5 minutes until translucent and soft.

Add the minced garlic, chopped reserved mushroom stems/gills, and optional diced button mushrooms. Cook, stirring, for 3–4 minutes until the mixture releases moisture and most of it evaporates.

Stir in the chopped spinach and cook just until wilted, about 1–2 minutes. Remove the skillet from heat and let the vegetable mixture cool for 3–4 minutes.

Combine filling

In a mixing bowl, combine the cooled vegetable mixture with 4 oz softened cream cheese, 1/2 cup grated Parmesan, 1/2 cup shredded mozzarella, 1/4 cup bread crumbs, 2 tablespoons chopped parsley, 1 teaspoon thyme, 1/4 teaspoon red pepper flakes, 1/2 teaspoon salt and 1/4 teaspoon black pepper. Mix until well incorporated. Taste and adjust seasoning if needed.

If the filling seems too loose, add an additional tablespoon of breadcrumbs or refrigerate for 10 minutes to firm slightly. The filling should hold shape when scooped.

Spoon the filling into each prepared portabella cap, dividing evenly among the 4 caps and mounding slightly.

Top each stuffed mushroom with an extra sprinkle of shredded mozzarella (about 1 tablespoon each) and an additional 1 teaspoon of bread crumbs for a slight crunch.

Drizzle each cap lightly with 1/4 teaspoon olive oil to help browning.

Bake in the preheated oven for 18–22 minutes, until the mushrooms are tender and the filling is bubbling and the tops are golden. For more browning, broil on high for 1–2 minutes—watch closely to avoid burning.

Remove from oven and let rest for 3–5 minutes. Garnish with chopped parsley and a squeeze of lemon if desired. Serve warm.