Caramelized Onion Tart

Buttery mini tarts filled with sweet caramelized onions and a hint of thyme. An elegant savory bite that turns the simplest allium into something worthy of a dinner party.

Caramelized Onion Tart

By Chef B. Boukim

Prep: 25 min · Cook: 45 min · Total: 1 hr 10 min · Serves 6

Ingredients

  • 1 sheet (14 oz) Puff pastry, thawed
  • 3 large Yellow onions, thinly sliced
  • 2 tbsp Butter
  • 1 tbsp Olive oil
  • 1 tsp Fresh thyme leaves
  • 1/2 cup Gruyère cheese, grated
  • 1/4 cup Heavy cream
  • 1 Egg
  • 1 tsp Sea salt
  • 1/2 tsp Black pepper

Instructions

  1. Heat butter and olive oil in a skillet over medium-low heat. Add the onions and salt. Cook slowly, stirring often, until deeply caramelized and jammy, about 30 minutes.
  2. Stir in the thyme during the last 2 minutes. Remove from heat and let cool slightly.
  3. Preheat the oven to 400°F (200°C). Unfold the puff pastry on a parchment-lined baking sheet and score a 1-inch border around the edge with a knife (do not cut through).
  4. Whisk the egg and cream together, then fold into the cooled onions. Season with pepper.
  5. Spread the onion mixture inside the border of the pastry. Sprinkle with Gruyère.
  6. Bake for 25-30 minutes until the pastry is puffed and golden and the cheese is bubbling.
  7. Let cool for 10 minutes, then slice and serve warm.