Name: Caramelized Onion-Stuffed Mushrooms
Prep time: 20 min
Cook time: 30 min
Total time: 1 h
Yield: 4
Cuisine: Italian-inspired
Ingredients: 16 medium-sized button or cremini mushrooms; 2 large yellow onions, thinly sliced; 2 tbsp olive oil; 1 tbsp butter; 2 garlic cloves, minced; 1/2 cup panko breadcrumbs; 1/3 cup grated Parmesan cheese; 1/4 cup shredded mozzarella cheese; 2 tbsp fresh parsley, chopped (plus extra for garnish); 1 tsp fresh thyme leaves (or 1/2 tsp dried thyme); Salt and pepper to taste

These caramelized onion-stuffed mushrooms are the perfect combination of earthy mushrooms and sweet, golden-brown onions. Enhanced with a cheesy breadcrumb topping, they deliver a comforting, savory flavor in every bite. This appetizer is easy to prepare yet impressive enough for gatherings. Serve them as a starter, side, or elegant party finger food.

Recipe Tips and Tricks

Choose the right mushrooms: Button or cremini mushrooms work best as they hold their shape and provide the perfect bite-sized vessel.
Caramelize onions slowly: Patience is key to achieving a deep, rich sweetness without burning.
Season generously: Don’t skimp on seasoning for the filling, as it’s the heart of the dish.
Avoid soggy mushrooms: Pre-bake the mushroom caps for a few minutes to release excess moisture before stuffing.
Add texture: Incorporate panko breadcrumbs for a light, crispy topping.

Why You’ll Love This Recipe

This recipe brings together simplicity and elegance. The mushrooms’ earthy flavors pair beautifully with the sweetness of caramelized onions, creating a harmonious blend of textures and tastes. Perfect for parties, family dinners, or even as a vegetarian main course, these stuffed mushrooms are sure to win over guests and food enthusiasts alike. They’re versatile, easy to customize, and can be prepared ahead of time, making them a stress-free option for any occasion.

Yield: Serves 4

Caramelized Onion-Stuffed Mushrooms

Juicy mushrooms stuffed with sweet caramelized onions, breadcrumbs, and cheese, baked to golden perfection—a delightful, crowd-pleasing appetizer.

Prep Time 20 minutes

Cook Time 30 minutes

Additional Time 10 minutes

Total Time 1 hour

Ingredients

16 medium-sized button or cremini mushrooms
2 large yellow onions, thinly sliced
2 tbsp olive oil
1 tbsp butter
2 garlic cloves, minced
1/2 cup panko breadcrumbs
1/3 cup grated Parmesan cheese
1/4 cup shredded mozzarella cheese
2 tbsp fresh parsley, chopped (plus extra for garnish)
1 tsp fresh thyme leaves (or 1/2 tsp dried thyme)
Salt and pepper to taste

Instructions

Prepare the Mushrooms: Preheat the oven to 375°F (190°C). Remove the mushroom stems and scoop out a bit of the center to create room for the filling. Arrange the caps on a baking sheet lined with parchment paper. Bake for 10 minutes, then set aside to cool.
Caramelize the Onions: Heat olive oil and butter in a skillet over medium heat. Add the onions with a pinch of salt, stirring occasionally for 20-25 minutes until golden and caramelized. Add garlic and cook for an additional minute.
Prepare the Filling: In a bowl, mix the caramelized onions, panko breadcrumbs, Parmesan cheese, mozzarella, parsley, thyme, salt, and pepper. Taste and adjust seasoning as needed.
Stuff the Mushrooms: Fill each mushroom cap generously with the prepared mixture, pressing slightly to ensure the filling stays in place.
Bake to Perfection: Return the stuffed mushrooms to the oven and bake for 15-20 minutes, until the tops are golden and bubbly. Garnish with fresh parsley before serving.

Notes

Double the recipe for larger gatherings.
Pre-caramelize onions and refrigerate to save time on the day of preparation.

Nutrition Information

Yield

Serving Size

1
Amount Per Serving Calories 226Total Fat 14gSaturated Fat 5gTrans Fat 0gUnsaturated Fat 8gCholesterol 18mgSodium 386mgCarbohydrates 19gFiber 2gSugar 4gProtein 7g

The recipes and nutritional information on Fungi Recipes are for informational purposes only. Always consult a healthcare provider for personalized dietary advice.

Ingredient Notes

Mushrooms: Use medium-sized button or cremini mushrooms; they’re sturdy and flavorful. Wash them gently and pat them dry to avoid soaking.
Onions: Yellow onions are ideal for caramelizing due to their natural sweetness, but red onions can add a bolder flavor.
Cheese: Parmesan provides a salty, nutty kick, while mozzarella melts beautifully for a creamy finish. Feel free to mix both.
Breadcrumbs: Panko adds a crunchy topping, but regular breadcrumbs work as well. Use seasoned ones for extra flavor.
Garlic and Herbs: Fresh thyme and parsley elevate the taste, but you can substitute dried herbs if needed.

Variations and Substitutions

Make it vegan: Replace cheese with nutritional yeast and use dairy-free butter for caramelizing the onions.
Add protein: Incorporate finely crumbled cooked sausage, bacon bits, or minced walnuts for added texture and flavor.
Spice it up: Add a pinch of chili flakes or cayenne for heat.
Cheese swap: Experiment with goat cheese, Gruyere, or sharp cheddar for different flavor profiles.
Gluten-free option: Use gluten-free breadcrumbs or omit them entirely and top with crushed nuts for crunch.

Storage Options

Refrigerator: Store leftovers in an airtight container for up to 3 days. Reheat in the oven at 350°F (175°C) for 10 minutes to maintain crispiness.
Freezer: Stuffed mushrooms can be frozen unbaked. Place them on a baking sheet, freeze until solid, and transfer to a freezer-safe bag. Bake from frozen, adding 5-10 minutes to the cooking time.