Roasted Tomato Tart
2.5C Unbleached AP Flour
12T Cold Unsalted Butter
3T Chilled Vegetable Shortening
8oz Gruyere cheese, grated
1/2C Shallots, caramelized
2 T Fresh Basil
1 slice Rustic White Bread
Several thinly sliced, ripe tomatoes, baked in the oven.
In a food processor, or by hand, combine flours and salt. Pulse to combine. Add butter and shortening and pulse until mixture resembles moist crumbs; do not overwork dough. Transfer to a bowl and sprinkle with 4 tablespoons of ice water. Shape into a ball, adding ice water 1 tablespoon at a time (as many as 6 more may be needed) until dough is just past crumbly and holds together.
For two tarts, divide dough in half and wrap each in plastic wrap, and press each with the palm of your hand into disks. For one tart, wrap in plastic and shape into one large disk. Refrigerate at least 30 minutes before rolling out. (I made several mini tarts instead.)
Preheat the oven to 400 degrees. Roll out dough into two 9-inch disks or one 10-by-16-inch rectangle 1/8-inch thick. Transfer to a baking sheet and crimp edges 1/2-inch high. Refrigerate for 30 minutes. Prick all over with a fork. Place parchment paper or foil on top and weigh down with pie weights or dried beans. Bake for 10 to 15 minutes. Remove paper or foil and weights from dough, and continue to bake another 5 minutes until dried slightly on top. Remove from the oven and set aside to cool; do not turn off the oven.
For topping: Spread mustard thinly over bottom of cooled shell. Sprinkle caramelized onions on top of the mustard. Scatter evenly with cheese. Whisk eggs and pour a thin layer over the cheese. Arrange tomatoes in even, slightly overlapping rows. Sprinkle with basil, season to taste with pepper and top with bread crumbs. Bake until the egg sets and the tart begins to brown and bubble. Approx. 20 minutes. Sprinkle with salt, and serve hot or at room temperature.