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French Onion Tart Recipe

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★★★★★

4.6 from 113 reviews

This French Onion Tart recipe combines the rich, caramelized flavors of sautéed onions with a creamy savory custard baked in a crisp pastry crust. Perfect as an elegant appetizer or light meal, this tart balances a flaky base with a luscious filling seasoned with thyme, salt, and pepper, making it a delightful dish for French cuisine lovers.

Ingredients

Scale

For the Tart Base

  • 1 sheet Shortcrust or Puff Pastry (store-bought or homemade, enough to fit a tart pan)

For the Filling

  • 4–5 medium onions (each about 2 inches broad), peeled and sliced
  • 1 tablespoon butter (for sautéing onions)
  • 2 large eggs
  • 1 cup table cream
  • 1 tablespoon dried thyme
  • ½ teaspoon salt
  • ¼ teaspoon ground black pepper

Instructions

  1. Prepare Onions: Peel and thinly slice 4-5 medium onions and set them aside for later use.
  2. Make Savory Custard: In a bowl, whisk together 2 large eggs, 1 cup table cream, 1 tablespoon dried thyme, ½ teaspoon salt, and ¼ teaspoon ground black pepper until smooth and well combined. Set aside this custard mixture.
  3. Prepare Pastry Shell: Roll out the pastry dough and fit it into a tart pan. Trim off any excess dough from the edges. Use a fork to prick holes evenly across the pastry base to prevent puffing during baking.
  4. Preheat Oven: Preheat your oven to 400°F (200°C) to get ready for blind baking and final baking stages.
  5. Bake Pastry Blind: Place a baking sheet cut to fit inside the tart shell and fill it with pie weights or dry beans to weigh down the crust. Bake the crust alone (blind bake) for 15 minutes at 400°F (200°C) to prevent sogginess. This step can be skipped if desired but is recommended.
  6. Sauté Onions: Heat 1 tablespoon of butter in a pan over medium heat and sauté the sliced onions until they are soft and lightly caramelized. This usually takes about 10-15 minutes. Stir frequently to avoid burning.
  7. Assemble Tart: Spread the cooked onions evenly over the pre-baked tart crust. Then pour the prepared savory custard mixture on top of the onions, distributing it evenly.
  8. Bake Tart: Bake the assembled tart in the oven at 400-430°F (200-220°C) for 30 minutes or until the custard is set and the pastry is golden brown. Remove from oven and let cool slightly before serving.

Notes

  • You can use either shortcrust or puff pastry depending on your preference for a denser or flakier crust.
  • Blind baking the crust is optional but helps avoid a soggy base when adding the moist onion and custard filling.
  • Ensure onions are cooked thoroughly to bring out their sweetness and avoid excess moisture in the tart.
  • The baking temperature range allows some flexibility depending on your oven; just make sure the custard is fully set and crust is golden.
  • This tart pairs wonderfully with a fresh green salad or as part of a brunch spread.

Keywords: French onion tart, savory tart, caramelized onion tart, baked custard tart, French pastry, savory pie

Find it online: https://annakocht.com/french-onion-tart-recipe/