Portobello Stuffed Mushrooms with Spinach, Gruyère, and Parmesan Recipe

Introduction

Stuffed Portobello mushrooms make a delicious and hearty appetizer or side dish that’s packed with flavor. These mushrooms are filled with a savory mixture of sautéed spinach, cheese, and herbs, then baked to golden perfection. Perfect for a cozy night or a special occasion.

Ingredients

• 4 large Portobello mushrooms
• 2 tablespoons olive oil
• 1/2 small onion, finely diced
• 2 cloves garlic, minced
• 2 sprigs fresh thyme, stalks removed
• 2 cups fresh spinach, chopped
• 1/2 cup breadcrumbs
• 1/2 cup Gruyère cheese, shredded
• 1/4 cup Parmesan cheese, grated
• 2 tablespoons fresh parsley, finely chopped
• Salt and pepper, to taste

Instructions

1. Step 1: Preheat the oven to 375ºF. Line a baking sheet with parchment paper and set aside.
2. Step 2: Wipe the mushrooms clean with a damp paper towel. Remove the stalks, finely chop them, and discard the gills from inside the caps.
3. Step 3: Place the mushrooms on the baking sheet, open side up. Bake for 15 minutes to release their moisture. Reserve any juice released.
4. Step 4: Heat olive oil in a skillet over medium heat. Add diced onions and sauté for about 2 minutes until softened, then add garlic, chopped mushroom stalks, and thyme. Cook for 1 more minute.
5. Step 5: Stir in the chopped spinach and reserved mushroom juice. Cook for 1-2 minutes until spinach wilts, then remove from heat.
6. Step 6: Add breadcrumbs, Gruyère, Parmesan, salt, and pepper to the skillet. Mix everything until well combined.
7. Step 7: Spoon the filling evenly into the mushroom caps, pressing gently to fill them well.
8. Step 8: Bake the stuffed mushrooms for 15-20 minutes, until tender and the cheese on top is melted and golden.
9. Step 9: Sprinkle with chopped parsley, extra thyme leaves, and a little more Parmesan before serving.

Tips & Variations

• For a vegan version, substitute the cheeses with plant-based alternatives or nutritional yeast.
• Add cooked sausage or bacon bits to the filling for a meatier option.
• Use panko breadcrumbs for a lighter, crispier texture.
• Be sure to remove the mushroom gills to prevent the filling from becoming too wet.

Storage

Store leftover stuffed mushrooms in an airtight container in the refrigerator for up to 3 days. Reheat gently in the oven at 350ºF for about 10 minutes to keep them tender without drying out.

How to Serve

Serve this delicious recipe with your favorite sides.

FAQs

Can I prepare these stuffed mushrooms in advance?

Yes, you can assemble the mushrooms a few hours ahead and keep them covered in the fridge. Bake just before serving for best results.

What can I use instead of Gruyère cheese?

You can substitute Gruyère with mozzarella, Swiss cheese, or even Fontina for a similar creamy, melty texture.

Portobello Stuffed Mushrooms with Spinach, Gruyère, and Parmesan Recipe

---

★★★★★

4.5 from 124 reviews

• Author: Hugo
• Total Time: 50 minutes
• Yield: 4 servings 1x
• Diet: Vegetarian

Pin Recipe

Print Recipe

Description

These Portobello Stuffed Mushrooms make for a delightful appetizer or light meal. Large Portobello mushrooms are pre-baked, then filled with a savory mixture of sautéed onions, garlic, fresh thyme, spinach, mushroom stalks, breadcrumbs, and a creamy blend of Gruyère and Parmesan cheeses. Baked until golden and bubbling, they offer a perfect balance of earthy flavors and cheesy richness, garnished with fresh parsley and additional cheese for a beautiful presentation.

---

Ingredients

Scale 1x2x3x

Mushrooms

• 4 large Portobello mushrooms
• 2 tablespoons olive oil

Vegetables and Herbs

• 1/2 small onion, finely diced
• 2 cloves garlic, minced
• 2 sprigs fresh thyme, stalks removed
• 2 cups fresh spinach, chopped
• 2 tablespoons fresh parsley, finely chopped

Cheese and Breadcrumbs

• 1/2 cup breadcrumbs
• 1/2 cup Gruyère cheese, shredded
• 1/4 cup Parmesan cheese, grated

Seasoning

• Salt and pepper to taste

---

Instructions

1. Preheat Oven: Preheat your oven to 375ºF (190ºC) and line a baking sheet with parchment paper to prevent sticking.
2. Prepare Mushrooms: Wipe the Portobello mushrooms clean with a damp paper towel. Carefully remove the stalks, finely chop them, and discard the mushroom gills from inside the caps. Place the mushroom caps open side up on the baking sheet.
3. Pre-Cook Mushrooms: Bake the mushrooms in the oven for 15 minutes. During this time, they will release water, which should be reserved for later use in the filling to add flavor and moisture.
4. Sauté Aromatics: Heat a skillet or cast iron pan over medium heat and add the olive oil. Once hot, add the diced onion and sauté until softened, about 2 minutes. Add the minced garlic, chopped mushroom stalks, and fresh thyme, cooking for another minute until fragrant.
5. Cook Spinach and Add Mushroom Juice: Stir in the chopped spinach and reserved mushroom juice. Cook for 1 to 2 minutes until the spinach wilts, then remove the pan from heat.
6. Combine Filling Ingredients: To the skillet, add the breadcrumbs, shredded Gruyère, grated Parmesan, salt, and pepper. Mix everything thoroughly until well combined and evenly incorporated.
7. Stuff Mushrooms: Divide the prepared filling evenly among the mushroom caps, gently pressing the mixture down into each one to ensure it’s packed well.
8. Bake Stuffed Mushrooms: Return the stuffed mushrooms to the oven and bake for an additional 15 to 20 minutes, or until the mushrooms are tender, the cheese has melted, and the tops turn golden brown.
9. Garnish and Serve: Once baked, sprinkle the mushrooms with chopped parsley, a few extra thyme leaves, and some additional grated Parmesan cheese for garnish. Serve warm.

Notes

• Reserve the mushroom juice after pre-baking to incorporate into the filling for enhanced flavor and moisture.
• Use fresh herbs like thyme and parsley to boost the recipe’s aroma and brightness.
• Gruyère cheese adds a creamy, slightly nutty taste; substitute with mozzarella or fontina if unavailable.
• Ensure the mushrooms are wiped clean; avoid washing them with water to prevent sogginess.
• This recipe serves well as an appetizer or light vegetarian main course.

• Prep Time: 15 minutes
• Cook Time: 35 minutes
• Category: Appetizer
• Method: Baking
• Cuisine: American

Keywords: Portobello mushrooms, stuffed mushrooms, baked mushrooms, vegetarian appetizer, Gruyère, Parmesan, spinach stuffing