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Caramelized Onion & Gruyère Puff Pastry Tart

Savor the Comfort of Caramelized Onion & Gruyère Puff Pastry Tart

A cozy and delicious Caramelized Onion & Gruyère Puff Pastry Tart that's quick to prepare and a total crowd-pleaser.
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Prep Time 30 minutes
Cook Time 18 minutes
Cooling Time 10 minutes
Total Time 58 minutes
Servings: 8 slices
Course: Dinner
Cuisine: French
Calories: 350
Ingredients Equipment Method Nutrition Notes

Ingredients
  

Tart Base
  • 1 sheet Puff Pastry Thawed frozen for best texture.
  • 2 tablespoons Butter Can substitute with olive oil for dairy-free.
Filling
  • 1 tablespoon Olive Oil Enhances flavor and helps caramelize onions.
  • 2 Yellow Onions Sliced for caramelization.
  • 1 tablespoon Sugar Aids in caramelization.
  • 1 pinch Salt Balances flavors.
  • ½ cup Heavy Cream Use non-dairy cream for lactose-free.
  • 1 large Egg Beaten, binds the filling.
  • 1 pinch Black Pepper Adds a slight kick.
  • 1 cup Gruyère Cheese Grated, can substitute with sharp cheddar.
  • 1 tablespoon Dijon Mustard Optional, adds extra tang.
  • 1 tablespoon Fresh Thyme Optional garnish.

Equipment

  • skillet
  • Mixing bowl
  • oven
  • Parchment paper
  • knife
  • Fork

Method
 

Cooking Instructions
  1. In a large skillet, melt 2 tablespoons of butter with 1 tablespoon of olive oil over medium heat. Add 2 sliced yellow onions, 1 tablespoon of sugar, and a pinch of salt. Cook gently for 25-30 minutes until golden brown.
  2. Preheat your oven to 400°F (200°C) while the onions caramelize.
  3. Roll out a sheet of thawed puff pastry into a rectangle, about 10x14 inches. Score a 1-inch border around the edges.
  4. In a mixing bowl, whisk together ½ cup of heavy cream, 1 beaten egg, and a pinch of black pepper. Stir in 1 cup of grated Gruyère cheese.
  5. Spread a thin layer of Dijon mustard on the pastry, pour the cheesy mixture over it, and top with caramelized onions.
  6. Bake for 15-18 minutes until the pastry is puffed and golden brown.
  7. Let it cool slightly, then sprinkle fresh thyme and sea salt on top before serving.

Nutrition

Serving: 1sliceCalories: 350kcalCarbohydrates: 30gProtein: 8gFat: 22gSaturated Fat: 12gPolyunsaturated Fat: 1gMonounsaturated Fat: 10gCholesterol: 80mgSodium: 600mgPotassium: 200mgFiber: 2gSugar: 3gVitamin A: 500IUVitamin C: 5mgCalcium: 150mgIron: 1mg

Notes

Allow the tart to cool slightly for cleaner slices. Store leftovers in an airtight container for up to 3 days.

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