Preparation Steps

• Preheat your oven to 375°F (190°C). Lightly grease a baking sheet.
• Wipe the portobello mushrooms clean. Remove the stems and gently scrape out the dark gills from the underside of the caps with a spoon. Brush the outside of the mushroom caps with 2 tablespoons of olive oil.
• In a large skillet, heat the remaining 2 tablespoons of olive oil over medium heat. Add the chopped onion and cook until softened, about 5-7 minutes. Add the minced garlic and cook for another minute until fragrant.
• Add the chopped spinach to the skillet. Cook, stirring, until wilted, about 3-5 minutes. Remove from heat and let it cool slightly.
• In a medium bowl, combine the softened cream cheese, mozzarella cheese, Parmesan cheese, salt, and pepper. Stir until well combined.
• Add the wilted spinach mixture to the cheese mixture and stir to combine thoroughly.
• Place the prepared mushroom caps on the greased baking sheet, gill-side up. Spoon the spinach and cheese filling evenly into each mushroom cap.
• Bake for 20-25 minutes, or until the mushrooms are tender and the filling is golden and bubbly.
• Let cool slightly before serving.