French Onion Soup Stuffed Mushrooms
These French Onion Soup Stuffed Mushrooms are made with tender button or crimini mushrooms, sweet caramelized onions, melted Gruyere cheese, and a few simple seasonings. An easy vegetarian stuffed mushrooms to make in no time.
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It’s a warm appetizers perfect for holidays, family gatherings, dinner parties, and other special occasions. They are especially good served hot right from the oven, with the mushrooms tender, the onions soft and jammy, and the cheese melted and lightly browned on top.
And for more mushroom stuffed recipes, the recipes below are worth trying:
Ingredients You’ll Need:
- 1 lb (450g) medium button or crimini mushrooms, about 12–16
- 2 medium (300g) sweet yellow onions, sliced
- 2 tablespoons (26g) unsalted butter
- ½ cup (120ml) broth
- ½ teaspoon (1g) garlic powder
- ½ teaspoon (½g) dried thyme
- ½ teaspoon (1g) ground black pepper
- ½ cup (60g) grated Gruyere or Swiss cheese
- Fresh parsley or thyme, for garnish
How to Make French Onion Soup Stuffed Mushrooms
Step 1: Slice the onions into thin quarter circles.
Step 2: Melt the butter in a large frying pan over medium heat.
Add the sliced onions and cook, stirring frequently, for 7–9 minutes, until they begin to brown.
Step 3: Reduce the heat to medium-low. Add the broth, garlic powder, dried thyme, and black pepper. Stir well, scraping up any browned bits from the bottom of the pan.
Step 4: Continue cooking for 12–15 minutes, stirring occasionally, until the onions are very soft, deeply browned, and reduced. Taste and add salt as needed, depending on the saltiness of your broth.
While the onions cook, wash and dry the mushrooms. Remove the stems and clean out the centers to create enough room for the filling.
Step 5: Preheat the oven to 400°F (200°C). Line a baking pan with parchment paper for easier cleanup.
Place the mushrooms hole-side up on the prepared pan.
Step 6: Spoon a small amount of the onion mixture into each mushroom, filling them tightly.
Step 7: Sprinkle a small mound of grated cheese over each mushroom.
Step 8: Bake for 10–15 minutes, until the mushrooms are cooked through and the cheese is melted and browned in spots.
Important Recipe Notes
- Choose larger mushrooms: Medium to large mushrooms with thick stems work best because they leave more room for the caramelized onion filling.
- Make the onions ahead: The caramelized onion mixture can be made up to 2 days in advance. Store it in a covered container in the refrigerator until you’re ready to use it.
- Prepare the mushrooms ahead: You can clean and prepare the mushrooms up to 1 day ahead. Store them in a tightly sealed container in the refrigerator with a paper towel inside to help absorb excess moisture.
- Serve hot: These are best enjoyed warm from the oven while the cheese is melted and the onions are soft and flavorful.
- Naturally gluten-free: When using a gluten-free broth, these make a naturally gluten-free warm appetizer that is great for holiday gatherings.
French Onion Soup Stuffed Mushrooms
Ingredients
- 1 lb 450g medium button or crimini mushrooms , about 12–16
- 2 medium 300g sweet yellow onions, sliced
- 2 tablespoons 26g unsalted butter
- ½ cup 120ml broth
- ½ teaspoon 1g garlic powder
- ½ teaspoon ½g dried thyme
- ½ teaspoon 1g ground black pepper
- ½ cup 60g grated Gruyere or Swiss cheese
- Fresh parsley or thyme for garnish
Instructions
- Slice the onions into thin quarter circles.
- Melt the butter in a large frying pan over medium heat.
- Add the sliced onions and cook, stirring frequently, for 7–9 minutes, until they begin to brown.
- Reduce the heat to medium-low. Add the broth, garlic powder, dried thyme, and black pepper. Stir well, scraping up any browned bits from the bottom of the pan.
- Continue cooking for 12–15 minutes, stirring occasionally, until the onions are very soft, deeply browned, and reduced. Taste and add salt as needed, depending on the saltiness of your broth.
- While the onions cook, wash and dry the mushrooms. Remove the stems and clean out the centers to create enough room for the filling.
- Preheat the oven to 400°F (200°C). Line a baking pan with parchment paper for easier cleanup.
- Place the mushrooms hole-side up on the prepared pan.
- Spoon a small amount of the onion mixture into each mushroom, filling them tightly.
- Sprinkle a small mound of grated cheese over each mushroom.
- Bake for 10–15 minutes, until the mushrooms are cooked through and the cheese is melted and browned in spots.
- Garnish with fresh parsley or thyme and serve hot.
