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 and Gruyère Tart Recipe

5 Stars 4 Stars 3 Stars 2 Stars 1 Star 4.4 from 37 reviews
  • Author: admin
  • Prep Time: 15 minutes
  • Cook Time: 50 minutes
  • Total Time: 65 minutes
  • Yield: 6 servings
  • Category: Tart
  • Method: Baking
  • Cuisine: French

Description

A savory and elegant Caramelized Onion and Gruyère Tart featuring sweet, slow-cooked onions layered on buttery puff pastry and topped with melted Gruyère cheese and fresh thyme. Perfect as an appetizer, brunch, or light meal.


Ingredients

Scale

For the Tart

  • 1 sheet puff pastry (thawed)
  • 2 large onions, thinly sliced
  • 2 tablespoons olive oil
  • 1 tablespoon butter
  • 1 cup Gruyère cheese, grated
  • 1 tablespoon fresh thyme leaves
  • Salt and pepper to taste
  • 1 egg (beaten, for egg wash)


Instructions

  1. Preheat Oven: Preheat your oven to 400°F (200°C) to prepare for baking the tart.
  2. Caramelize Onions: In a skillet over medium heat, warm the olive oil and butter. Add the thinly sliced onions and cook, stirring occasionally, for 20-25 minutes until they become golden brown and caramelized. Season the onions with salt, pepper, and fresh thyme leaves to enhance their flavor.
  3. Prepare Puff Pastry: On a floured surface, roll out the thawed puff pastry sheet to fit your tart pan. Transfer the pastry carefully into the pan and prick the bottom with a fork to prevent excessive puffing during baking.
  4. Assemble Tart: Evenly spread the caramelized onions over the puff pastry base. Sprinkle the grated Gruyère cheese evenly on top of the onions for a rich, melty layer.
  5. Apply Egg Wash: Brush the edges of the puff pastry with the beaten egg to help it develop a beautiful golden color while baking.
  6. Bake Tart: Place the tart in the preheated oven and bake for 25-30 minutes, or until the puff pastry is golden and crisp and the cheese is bubbling and slightly browned.
  7. Cool and Serve: Remove the tart from the oven and allow it to cool slightly before slicing and serving to let the flavors meld and the tart set.

Notes

  • Use a sharp knife to thinly slice onions evenly for consistent caramelization.
  • If puff pastry is not thawed, allow it to thaw in the refrigerator for several hours or overnight for best results.
  • Fresh thyme can be substituted with dried thyme, but use less (about 1 teaspoon) as dried herbs are more concentrated.
  • The tart is best served warm but can also be enjoyed at room temperature.
  • Store leftover tart in an airtight container in the refrigerator for up to 3 days and reheat gently before serving.