Print
clock clock iconcutlery cutlery iconflag flag iconfolder folder iconinstagram instagram iconpinterest pinterest iconfacebook facebook iconprint print iconsquares squares iconheart heart iconheart solid heart solid icon
Caramelized Onion & Gruyère Stuffed Mushrooms

Caramelized Onion & Gruyère Stuffed Mushrooms

  • Author: Laura
  • Prep Time: 15 minutes
  • Cook Time: 25 minutes
  • Total Time: 40 minutes
  • Yield: 12 stuffed mushrooms 1x
  • Category: Appetizer
  • Method: Baking
  • Cuisine: French-American
  • Diet: Vegetarian

Description

Caramelized Onion & Gruyère Stuffed Mushrooms are a savory and elegant appetizer, featuring tender mushroom caps filled with sweet caramelized onions and melted Gruyère cheese. Perfect for a party or as a fancy side dish, these stuffed mushrooms offer a deliciously rich flavor combination.


Ingredients

Scale
  • 12 large white or cremini mushrooms, stems removed
  • 2 tablespoons olive oil
  • 1 medium onion, thinly sliced
  • 1/4 teaspoon salt
  • 1/4 teaspoon black pepper
  • 1 tablespoon balsamic vinegar
  • 1/2 cup grated Gruyère cheese
  • 1/4 cup breadcrumbs (optional, for crunch)
  • 2 tablespoons fresh parsley, chopped (optional, for garnish)

Instructions

  1. Preheat the oven to 375°F (190°C) and line a baking sheet with parchment paper.
  2. Heat olive oil in a large skillet over medium heat. Add the sliced onions, salt, and pepper, and sauté for 10–12 minutes until the onions become soft and caramelized.
  3. Add balsamic vinegar to the onions, stirring to combine. Continue to cook for another 2–3 minutes, allowing the vinegar to reduce slightly. Remove from heat.
  4. Place the mushroom caps on the prepared baking sheet, cavity-side up. Spoon the caramelized onions evenly into each mushroom cap.
  5. Top each stuffed mushroom with grated Gruyère cheese and a sprinkle of breadcrumbs, if using.
  6. Bake for 15–20 minutes, or until the mushrooms are tender and the cheese is melted and golden brown.
  7. Remove from the oven and garnish with chopped parsley, if desired. Serve warm.

Notes

  • For extra richness, add a small amount of cream cheese or ricotta to the onion mixture before stuffing the mushrooms.
  • These stuffed mushrooms can be made ahead of time and baked just before serving.
  • Try adding a sprinkle of fresh thyme or rosemary for added flavor.

Nutrition

  • Serving Size: 1 stuffed mushroom
  • Calories: 80
  • Sugar: 3g
  • Sodium: 180mg
  • Fat: 5g
  • Saturated Fat: 1.5g
  • Unsaturated Fat: 3.5g
  • Trans Fat: 0g
  • Carbohydrates: 8g
  • Fiber: 1g
  • Protein: 3g
  • Cholesterol: 5mg

Keywords: stuffed mushrooms, caramelized onions, Gruyère cheese, savory appetizer, party food