Golden Onion Tart With Gruyère And Thyme

• For the dough (adapted from a recipe by Alice Waters)
• 1 cup all-purpose flour
• 1/2 teaspoon salt
• 6 tablespoons unsalted butter, chilled, cut in 1/4 inch cubes
• 3 tablespoons ice water
• For the filling:
• 2 tablespoons olive oil
• 2 pounds yellow onion, peeled and thinly sliced
• 1 teaspoon salt
• 2 tablespoons port wine
• 1 teaspoon freshly ground black pepper
• 2 ounces finely grated Gruyere cheese
• 1 teaspoon fresh thyme, plus extra for garnish
• 1 egg, slightly beaten

1. Stir flour and salt together with a fork. Toss in butter. Using fingertips, work the butter into the flour until it resembles coarse meal, with some pieces of the butter apparent. Sprinkle in the water while stirring with the fork until the dough comes together, adding another tablespoon of water if necessary. Form into a ball and flatten. Wrap in plastic wrap and refrigerate 1 hour.
2. Heat olive oil over medium heat in a deep skillet or pot. Add onions and salt. Cook onions, stirring occasionally, until they are golden brown, soft and squidgy, about 30 minutes. Add port wine and cook, stirring, 2 minutes. Remove onions from heat and stir in the pepper. Cool slightly.
3. While the onions are cooling, roll out the dough to fit in the bottom and up the side of a 10 inch round tart tin. Sprinkle half of the cheese over the bottom of the tart. Spoon onions into the shell and spread evenly. Sprinkle 1 teaspoon thyme over the onions. Brush the exposed crust rim with the egg wash. Sprinkle the tart and crust with the remaining cheese.
4. Bake in a preheated 375 F. oven until the crust is firm and golden and the onions have turned a rich golden brown, without blackening, about 30 minutes. Remove and cool slightly. Serve slightly warm or at room temperature garnished with thyme sprigs.

flour, salt, unsalted butter, water, olive oil, yellow onion, salt, port wine, freshly ground black pepper, gruyuere cheese, fresh thyme, egg

Taken from food52.com/recipes/10011-golden-onion-tart-with-gruyere-and-thyme (may not work)