Caramelized Onion and Mushroom Tartlets

Introduction

Caramelized Onion and Mushroom Tartlets are the epitome of sophistication meets simplicity. Their buttery, flaky crust cradles a savory filling of sweet caramelized onions and earthy mushrooms, creating a perfectly balanced bite that’s both rich and refined. These tartlets are ideal for every occasion—from elegant dinner parties to casual get-togethers or even a solo indulgence when you want to treat yourself.

What makes this recipe shine is the way simple ingredients come together to create a burst of flavor in every bite. The caramelized onions bring a natural sweetness that pairs beautifully with the umami-packed mushrooms, all nestled in a crisp tart shell that’s practically irresistible. And while they taste like they came from a gourmet bakery, they’re surprisingly easy to make at home!

You can customize these tartlets to suit your taste—add a sprinkle of thyme, a dash of balsamic glaze, or a dollop of creamy cheese for an extra indulgent touch. Serve them warm, and watch them disappear as quickly as you set them down.

Ready to make these elegant appetizers the star of your next gathering? Let’s get started on this delicious journey!

Why You’ll Love This Recipe

There’s so much to adore about these Caramelized Onion and Mushroom Tartlets:

  • Perfect for Entertaining: These are an ideal appetizer or party snack that will wow your guests.
  • Sophisticated Flavor: The sweet onions and savory mushrooms are a match made in culinary heaven.
  • Customizable: Add cheese, herbs, or spices to tailor the tartlets to your taste.
  • Simple Ingredients: Made with everyday pantry items.
  • Make-Ahead Friendly: Prepare components in advance for easy assembly.
  • Easy to Handle: Small and portable, they’re perfect finger food.
  • Vegetarian-Friendly: A great option for meatless gatherings.
  • Kid-Approved: Even picky eaters love the buttery crust and mild flavor.
  • Budget-Friendly: Uses affordable ingredients that pack a lot of flavor.
  • Beautiful Presentation: These tartlets look as good as they taste!

Preparation Time and Cook Time

  • Total Time: 1 hour
  • Preparation Time: 20 minutes
  • Cook Time: 40 minutes
  • Servings: 12 tartlets
  • Calories per tartlet: Approximately 140 calories
  • Key Nutrients: Fiber: 1g, Fat: 9g, Carbohydrates: 12g, Protein: 3g

Ingredients

Here’s what you’ll need to make these delicious tartlets:

For the Filling:

  • 2 large onions, thinly sliced
  • 2 cups mushrooms, diced (button, cremini, or your choice)
  • 2 tbsp olive oil
  • 1 tbsp butter
  • 1 tbsp balsamic vinegar
  • 1 tsp sugar
  • 1 tsp fresh thyme leaves (optional)
  • Salt and pepper, to taste

For the Tartlet Shells:

  • 1 package pre-made puff pastry, thawed
  • 1 egg, beaten (for egg wash)

Ingredient Highlights

  • Onions: Slow-cooked to a rich, caramelized sweetness that adds depth to the tartlets.
  • Mushrooms: Provide an earthy, umami-rich flavor.
  • Puff Pastry: A convenient way to achieve a flaky, buttery crust without the hassle of making dough from scratch.
  • Balsamic Vinegar: Adds a tangy-sweet note that elevates the filling.

Step-by-Step Instructions

Follow these simple steps to create your Caramelized Onion and Mushroom Tartlets:

Prepare the Filling

  1. Heat the Pan: In a large skillet, heat olive oil and butter over medium heat.
  2. Caramelize the Onions: Add the sliced onions and cook, stirring occasionally, for 15-20 minutes until golden and soft. Sprinkle with sugar and continue cooking for 5 minutes. Add balsamic vinegar, stir well, and remove from heat.
  3. Cook the Mushrooms: In the same pan, sauté the mushrooms until they release their moisture and turn golden brown, about 8-10 minutes. Season with thyme (if using), salt, and pepper. Combine the mushrooms with the caramelized onions.

Prepare the Tartlet Shells

  1. Preheat the Oven: Preheat your oven to 375°F (190°C).
  2. Roll the Puff Pastry: On a lightly floured surface, roll out the puff pastry to about 1/8-inch thickness.
  3. Cut the Dough: Use a round cookie cutter or a glass to cut out circles slightly larger than your tartlet molds.
  4. Assemble the Tartlets: Press the pastry circles into the tartlet molds or muffin tins. Spoon the onion and mushroom mixture evenly into each shell.
  5. Apply Egg Wash: Brush the edges of the pastry with beaten egg to give them a golden, glossy finish.

Bake the Tartlets

  1. Bake: Place the tartlets in the preheated oven and bake for 20-25 minutes, or until the pastry is puffed and golden brown.
  2. Cool Slightly: Allow the tartlets to cool for a few minutes before removing them from the molds. Serve warm or at room temperature.

How to Serve

Here are a few creative ways to present your tartlets:

  1. On a Platter: Arrange them on a beautiful serving tray for a stunning centerpiece.
  2. As Hors d’oeuvres: Serve on small plates with cocktail forks for an elegant touch.
  3. Paired with Wine: These tartlets pair wonderfully with a crisp white wine or a light red like Pinot Noir.
  4. On a Cheese Board: Add them to a cheese and charcuterie board for a delicious addition.
  5. For Brunch: Serve alongside a fresh salad or fruit platter for a hearty brunch option.

Additional Tips

Make your Caramelized Onion and Mushroom Tartlets even better with these helpful tips:

  1. Thaw the Puff Pastry Properly: Let it thaw in the refrigerator for a few hours to prevent tearing.
  2. Don’t Overfill: Keep the filling level with the pastry edges to avoid spills.
  3. Use a Non-Stick Pan: It makes removing tartlets easier.
  4. Experiment with Cheese: Sprinkle grated Parmesan, Gruyère, or goat cheese over the filling before baking for extra flavor.
  5. Prep Ahead: The onion and mushroom mixture can be made a day in advance and stored in the refrigerator.
  6. Add Herbs: Garnish with fresh parsley or thyme for a pop of color.
  7. Keep It Crisp: Serve immediately after baking to enjoy the crispiness of the puff pastry.

Recipe Variations

Customize your tartlets with these fun variations:

  • Add Cheese: Incorporate your favorite cheese into the filling or sprinkle on top before baking.
  • Make It Sweet: Add a drizzle of honey or fig jam for a sweet-savory twist.
  • Use Phyllo Dough: For a lighter texture, swap puff pastry for phyllo dough.
  • Add Protein: Include cooked bacon bits, pancetta, or shredded chicken for a heartier option.
  • Try Different Veggies: Swap mushrooms for bell peppers, zucchini, or spinach.
  • Herb Variations: Experiment with rosemary, sage, or dill for unique flavor profiles.
  • Mini Quiches: Mix the filling with a beaten egg for a quiche-like tartlet.
  • Gluten-Free: Use a gluten-free puff pastry to cater to dietary needs.

Freezing and Storage

Keep your tartlets fresh with these storage tips:

  • Refrigeration: Store leftovers in an airtight container in the fridge for up to 3 days.
  • Reheating: Reheat in the oven at 350°F for 10 minutes to restore their crispiness.
  • Freezing: Freeze unbaked tartlets on a baking sheet until solid, then transfer to a freezer-safe bag. Bake directly from frozen, adding 5-10 minutes to the baking time.

Special Equipment

Here’s what you might need to make these tartlets:

  • Tartlet Molds: For shaping the shells.
  • Rolling Pin: To flatten the puff pastry.
  • Cookie Cutter: For cutting perfect circles.
  • Pastry Brush: For applying the egg wash.

FAQ Section

If you have questions about making Caramelized Onion and Mushroom Tartlets, this section has you covered! Whether you’re curious about ingredient substitutions, storage tips, or how to make them ahead of time, we’ve included detailed answers to ensure your tartlets turn out perfectly every time. Read on to find helpful advice and tips for troubleshooting and customizing this recipe.

  • Can I use homemade dough?
    Yes, if you prefer, you can make your own shortcrust pastry or pie dough.
  • What mushrooms work best?
    Cremini or button mushrooms are great, but feel free to mix in shiitake or portobello for a richer flavor.
  • Can I make this vegan?
    Substitute puff pastry with a vegan version, use olive oil instead of butter, and skip the egg wash.
  • Can I make the tartlets ahead of time?
  • Yes! These tartlets are very make-ahead friendly. You can prepare the caramelized onions and sautéed mushrooms up to 2 days in advance and store them in the refrigerator. When ready to serve, assemble the tartlets and bake as directed. Alternatively, you can bake the tartlets ahead of time and reheat them in a 350°F (175°C) oven for 8-10 minutes before serving.
  • What kind of mushrooms should I use?
  • You can use any variety of mushrooms for this recipe, such as cremini, button, shiitake, or a mix of wild mushrooms. Cremini mushrooms are a great choice for their rich, earthy flavor, but feel free to experiment based on your taste preferences or what’s available.
  • Can I use store-bought tart shells?
  • Absolutely! Using pre-made tart shells is a great time-saver. Look for mini tart shells in the frozen section of your grocery store, or use puff pastry cut into small circles if you’re short on time.
Print
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Caramelized Onion and Mushroom Tartlets


  • Author: Christine
  • Total Time: 1 hour

Ingredients

Scale

For the Filling:

  • 2 large onions, thinly sliced
  • 2 cups mushrooms, diced (button, cremini, or your choice)
  • 2 tbsp olive oil
  • 1 tbsp butter
  • 1 tbsp balsamic vinegar
  • 1 tsp sugar
  • 1 tsp fresh thyme leaves (optional)
  • Salt and pepper, to taste

For the Tartlet Shells:

  • 1 package pre-made puff pastry, thawed
  • 1 egg, beaten (for egg wash)

Instructions

Prepare the Filling

  1. Heat the Pan: In a large skillet, heat olive oil and butter over medium heat.
  2. Caramelize the Onions: Add the sliced onions and cook, stirring occasionally, for 15-20 minutes until golden and soft. Sprinkle with sugar and continue cooking for 5 minutes. Add balsamic vinegar, stir well, and remove from heat.
  3. Cook the Mushrooms: In the same pan, sauté the mushrooms until they release their moisture and turn golden brown, about 8-10 minutes. Season with thyme (if using), salt, and pepper. Combine the mushrooms with the caramelized onions.

Prepare the Tartlet Shells

  1. Preheat the Oven: Preheat your oven to 375°F (190°C).
  2. Roll the Puff Pastry: On a lightly floured surface, roll out the puff pastry to about 1/8-inch thickness.
  3. Cut the Dough: Use a round cookie cutter or a glass to cut out circles slightly larger than your tartlet molds.
  4. Assemble the Tartlets: Press the pastry circles into the tartlet molds or muffin tins. Spoon the onion and mushroom mixture evenly into each shell.
  5. Apply Egg Wash: Brush the edges of the pastry with beaten egg to give them a golden, glossy finish.

Bake the Tartlets

  1. Bake: Place the tartlets in the preheated oven and bake for 20-25 minutes, or until the pastry is puffed and golden brown.
  2. Cool Slightly: Allow the tartlets to cool for a few minutes before removing them from the molds. Serve warm or at room temperature.
  • Prep Time: 20 min.
  • Cook Time: 40 min.

Nutrition

  • Serving Size: 12 tartlets
  • Calories: 140kcal
  • Fat: 9g
  • Carbohydrates: 12g
  • Fiber: 1g
  • Protein: 3g

Conclusion

These Caramelized Onion and Mushroom Tartlets are a bite-sized burst of flavor that’s sure to impress! With their perfectly flaky crust and a rich filling of sweet caramelized onions and savory mushrooms, they’re the ultimate appetizer for any occasion. Whether you’re hosting an elegant dinner party or enjoying a cozy night in, these tartlets bring a touch of gourmet to your table.

So grab your ingredients and get started on these irresistible bites of goodness. Don’t forget to snap a photo and tag me on social media—I love seeing your delicious creations! Happy cooking!

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