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Caramelized Onion Tart

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Caramelized Onion Tart is a savory pastry made with sweet, slow-cooked onions layered over a buttery crust. Enhanced with herbs and optional cheese or cream, it’s a versatile dish perfect for brunch, lunch, or as a starter.

Ingredients

  • 3–4 large yellow or sweet onions, thinly sliced
  • 2 tablespoons olive oil or butter
  • 1/2 teaspoon salt
  • 1/2 teaspoon sugar (optional)
  • 1 teaspoon fresh thyme or rosemary (optional)
  • 1 sheet puff pastry or shortcrust pastry (store-bought or homemade)
  • 2 eggs (optional, for custard filling)
  • 1/3 cup heavy cream or sour cream (optional)
  • 1/2 cup grated cheese (Gruyère, goat cheese, or Parmesan, optional)
  • Black pepper, to taste

Instructions

  1. Preheat oven to 375°F (190°C). Roll out pastry and fit it into a tart pan or onto a baking sheet. Prick the base with a fork and chill while preparing filling.
  2. Heat oil or butter in a skillet over medium-low heat. Add sliced onions and salt. Cook slowly for 30–40 minutes, stirring often, until golden and caramelized. Add sugar halfway through to enhance caramelization, if using.
  3. Add herbs during the last few minutes of cooking. Set onions aside to cool slightly.
  4. If using, whisk eggs and cream together in a small bowl. Season with salt and pepper.
  5. Spread the caramelized onions evenly over the pastry. Sprinkle with cheese if desired. Pour egg mixture over the top for a custard-style tart.
  6. Bake for 25–30 minutes, or until the pastry is golden and the filling is set.
  7. Cool slightly before slicing. Serve warm or at room temperature.

Notes

  • Onions must be cooked low and slow to develop deep flavor—don’t rush the caramelization process.
  • Puff pastry gives a light, flaky base; shortcrust pastry makes for a sturdier, buttery tart.
  • This tart can be made without eggs or dairy for a vegan version—just skip the custard base and cheese.
  • Pairs well with salad, soup, or served as part of a brunch spread.

Nutrition

Find it online: https://thefamilycooking.com/caramelized-onion-tart/