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Onion Tart Recipe
Ash Tyrrell

Onion Tart Recipe

When I made this onion tart last weekend, I couldn’t believe how easy it was to bring such an elegant dish to life. Think golden, caramelized onions resting on a creamy bed of Greek yogurt, all on top of a buttery, flaky puff pastry crust.
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Prep Time 10 minutes
Cook Time 35 minutes
Servings: 4
Ingredients Method Notes

Ingredients
  

  • 3 large sweet onions thinly sliced: Sweet onions offer a natural caramel-like flavor perfect for this dish.
  • 2 tablespoons olive oil: Helps sauté the onions to golden perfection without burning.
  • 1 sheet puff pastry store-bought or homemade: Be sure to thaw store-bought pastry overnight for best results.
  • 1 egg whisked with 1 tablespoon water: A simple egg wash gives the pastry its gorgeous golden color.
  • ½ cup Greek yogurt: Adds a tangy yet creamy contrast to the rich onions.
  • 2 tablespoons grated Parmesan cheese: Freshly grated for that extra nutty savory kick.
  • 1 teaspoon fresh thyme leaves or ½ teaspoon dried thyme: Adds a fragrant touch that pairs beautifully with the onions.
  • Salt and pepper to taste: Seasoning ties the flavors together perfectly.

Method
 

  1. Start by heating olive oil in a skillet over medium-low heat. Add your sliced onions with a pinch of salt and stir occasionally. Cook slowly for about 15-20 minutes until they’re soft, golden brown, and caramelized. Remove from the heat and set aside to cool.
  2. Roll out the puff pastry into a 10x10-inch square on parchment paper. If using store-bought pastry, thaw it thoroughly and trim any uneven edges.
  3. Lightly score a 1-inch border around the edges to create a crust. This border will puff up as it bakes to frame your tart.
  4. Brush the border of the pastry with egg wash to ensure a golden, crisp crust. Spread the Greek yogurt evenly over the center of the pastry, steering clear of the edges. Sprinkle freshly grated Parmesan over the yogurt for a cheesy layer of flavor.
  5. Top the yogurt mixture with your cooled caramelized onions, spreading them evenly across the center. Sprinkle thyme leaves on top, and season generously with salt and pepper.
  6. Preheat your oven to 400°F (200°C). Slide the parchment paper and tart onto a baking sheet, then bake for 20-25 minutes. The pastry should be golden brown and puffed around the edges. Once baked, cool the tart for 10 minutes before slicing and serving.

Notes

  • Don’t Rush the Onions: Slow cooking is key to caramelizing natural sugars in the onions without burning them.
  • Egg Wash Carefully: Be precise while brushing the egg wash to avoid sealing the edges of the puff pastry layers.
  • Cool Before Serving: This allows the flavors to meld together for a more cohesive and delicious bite.