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French Onion Soup Stuffed Mushrooms Recipe – My favorite French Onion Soup meets stuffed mushrooms in this delicious appetizer recipe!
Oh my goodness, friends! If you love French Onion Soup as much as we do and also love mushrooms, then this is a recipe that I think you absolutely NEED!
French Onion Soup Stuffed Mushrooms Recipe
Filled with everything I love about French Onion Soup all stuffed into a delicious mushroom cap and then roasted to perfect, this makes an appetizer that I think you’ll just love.
How to Make French Onion Soup Stuffed Mushrooms
To make the stuffed mushrooms, I start by cleaning my mushrooms with a damp paper towel. Then, I carefully remove the stems of the mushrooms and place the mushroom caps on a parchment paper lined baking sheet.
Chop your mushroom stems and your onions thinly and then cook in a skillet over medium heat until your onions are tender and caramelized.
Meanwhile, I pulse a piece of sourdough bread (you can use whatever bread you have on hand) in my blender for a few seconds along with my Stone House Seasoning. You can also use a food processor to make your homemade bread crumbs. They only take a second. If you’d prefer though, you can definitely use store-bought bread crumbs. If using those, I would recommend the unseasoned and then add your own seasonings.
I fill each of my mushroom caps with the seasoned bread crumbs.
And then top them with the caramelized onions and mushroom stems.
Oh my goodness, they already look scrumptious!
Next comes the grated cheeses and another quick sprinkle of seasonings and then into the oven for a few minutes to bake.
I added a sprinkle of fresh parsley as it came out of the oven and voila!
How to Make-Ahead French Onion Soup Stuffed Mushrooms
This appetizer recipe is perfect for serving when entertaining, but if you are like me, you like to have many of your items made ahead for parties, holiday gatherings, having friends over for dinner, or even on game days! That’s one of the things I really love about this recipe. You can totally make assemble ahead so that all you have to do to serve them at your event is just bake, allow to rest a few minutes and serve! That’s it!
I make the recipe all the way up until baking the stuffed mushrooms and then just cover my baking sheet and store the stuffed mushrooms in the refrigerator for up to 3 days. Then, about 45 minutes before I plan to serve them or even earlier since they are delicious at room temperature, I remove the cover of my baking sheet and bake them as directed. They may take just a few more minutes since they are baking from the refrigerator.
Here’s my French Onion Soup Stuffed Mushrooms Recipe.
French Onion Soup Stuffed Mushrooms Recipe
- 24 whole fresh mushrooms cleaned and stems removed with stems chopped
- 1 medium onion thinly sliced
- 1 tablespoon butter
- 1/4 cup beef stock or broth
- 1 slice sourdough bread
- 1/2 teaspoon Stone House Seasoning
- 1/2 cup grated Gruyere cheese
- 1/4 cup grated Parmesan cheese
- chopped fresh parsley optional
- Preheat oven to 450º F. Arrange clean mushroom caps with the open cavity up on a parchment paper lined baking sheet.
- Add chopped mushroom stems, sliced onion, and butter to a medium skillet set over medium heat. Cook until the onions are tender, about 7 minutes. Add the beef stock and cook until the onions are glazed and caramelized, about 10 more minutes.
- Meanwhile, pulse the bread in a blender or food processor until you have made breadcrumbs. Toss with Stone House Seasoning and fill each of the mushroom caps with the seasoned bread crumbs.
- Top the breadcrumbs with the onion mixture and then top with grated cheeses. Bake in the oven for 15 minutes. Remove from the oven and allow to rest on the pan to cool slightly before serving, about 5 minutes. Top with fresh parsley, if using, and serve.
Prepare French Onion Soup Stuffed Mushrooms as directed without baking. Cover the baking sheet and store in the refrigerator up to 3 days. At least 45 minutes prior to time to serve, remove the cover of the baking sheet and bake as directed. The stuffed mushrooms may take an additional few minutes to cook if baking straight from the refrigerator.