Caramelized Onion, Mushroom & Gruyere Tartlets

These vegetarian tartlets are perfect to serve as an easy appetizer

Course Appetizer
Cuisine American
Prep 20 minutes
Cook 40 minutes
Total 1 hour
Servings 16 3-inch tartlets
Calories 71 kcal
Author Michelle


  • 1 tablespoon olive oil
  • 1 large yellow onion thinly sliced
  • 1 tablespoon unsalted butter
  • 16 ounces white button mushrooms thinly sliced
  • 1 clove garlic chopped
  • ½ teaspoon dried thyme
  • Salt and pepper to taste
  • ¼ cup white wine can substitute chicken or vegetable broth
  • 2 sheets puff pastry thawed according to directions on package
  • 1 cup shredded Gruyere cheese can substitute any variety of Swiss cheese
  • 1 egg + 1 tablespoon water beaten together (for the egg wash)
  • Handful of parsley chopped
US Customary - Metric


  1. Preheat oven to 400 degrees F and line two baking sheets with parchment paper.
  2. Heat the olive oil in a wide, heavy-bottomed pan over medium-low heat and add the onions. Cook, stirring occasionally, until they begin to caramelize, about 20 minutes.
  3. Add the butter to the pan. Once melted, add the mushrooms and saute, stirring occasionally, until they are completely soft and all of the liquid evaporates, about 20 minutes.
  4. Add the garlic and the thyme and saute until fragrant, about 1 minute. Season with salt and pepper to taste.
  5. Add the wine, scraping the bottom of the pan to pull up all of the browned bits, and cook until all of the liquid has evaporated. Remove from heat.
  6. Unfold the thawed sheets of puff pastry and cut out circles from the dough, placing them evenly spaced on the baking sheets. Using a very sharp knife, make four small scores around the perimeter of the dough, about ¼ to ½-inch from the edge.
  7. Top the rounds of puff pastry with a small spoonful of the onion and mushroom mixture, trying to keep the filling within the score marks. Top with the shredded Gruyere cheese. Brush the edges of the dough rounds with the egg wash.
  8. Bake until the pastry is golden brown, about 15 to 25 minutes. Garnish with fresh chopped parsley.
Nutrition Facts
Caramelized Onion, Mushroom & Gruyere Tartlets
Amount Per Serving
Calories 71 Calories from Fat 45
% Daily Value*
Fat 5g8%
Saturated Fat 2g13%
Cholesterol 21mg7%
Sodium 38mg2%
Potassium 113mg3%
Carbohydrates 2g1%
Protein 3g6%
Vitamin A 140IU3%
Vitamin C 1.6mg2%
Calcium 87mg9%
Iron 0.3mg2%
* Percent Daily Values are based on a 2000 calorie diet.