Breton Onion Tart

2011 Mar/Apr


For Onion Marmalade:

  • 2 oz. bacon, cut into large chunks
  • 1/4 c. olive oil
  • 2 large yellow onions, thinly sliced
  • 1/4 c. balsamic vinegar
  • 1/8 c. sherry vinegar
  • 1/2 c. water
  • 1 t. salt
  • 1/4 t. ground pepper
  • 2 t. sugar
  • 1/2 t. cayenne pepper

For Pastry and filling:

  • 1 lb. puff pastry, chilled
  • 2 large eggs
  • 1 c. crème fraîche or sour cream
  • salt and pepper to taste


To make the marmalade, heat a pan and add the chunks of bacon and sauté them until they’re slightly crisp, about 2 minutes. Add the olive oil and sliced onions, and continue to sauté the mixture until the onions are golden brown, about 15 minutes. Stir in the balsamic and sherry vinegars, water, salt, pepper, sugar and cayenne. Over medium heat, cook the marmalade until the liquid evaporates completely, 12 to 15 minutes.

Roll out the puff pastry (to approx. 1/8-inch thick), on a lightly floured work surface, to form a round 11-1/2 inches to fit a 10-1/2-inch tart pan with removable bottom. Transfer the pastry to the pan, fitting it against the bottom and sides and trimming off the excess pastry. Refrigerate the pastry shell for 1/2 hour.

Preheat the oven to 425°F. Remove the pastry shell from the refrigerator, prick it all over with a fork and line it with foil. Bake in the centre of the oven until the edges of the pastry turn golden, approximately 15 minutes. Remove the foil and continue baking the tart shell until the pastry is cooked through and pale golden, about another 10 to 15 minutes. Remove the tart shell from the oven and let it cool slightly.

In a medium-sized bowl, whisk together the eggs and the crème fraîche. Add the onion marmalade and mix it in until it’s thoroughly blended. Season the mixture with salt and pepper.

Place the pastry shell on a baking sheet. Pour the filling mixture into the pastry shell, and bake the tart in the centre of the oven until it’s golden and slightly puffed, 25 to 30 minutes. To test for doneness, shake the tart. If it’s loose in the centre, bake it for an additional 5 minutes, or until it’s set. Remove the tart from the oven, and let it cool for at least 5 to 10 minutes before serving it. Serves 4 to 6; serve with the endive salad.