for the pastry
2 1/2 cups all purpose flour
1 tablespoon sugar
3/4 teaspoon salt
10 tablespoons (1 1/4 sticks) chilled unsalted butter, cut into 1/2-inch pieces
1/3 cup chilled solid vegetable shortening, diced
6 tablespoons (or more) ice water
For the filling
6 quince, peeled, cored and dices
1/2 cup brown sugar
4 tablespoons unsalted butter
dash of cinnamon
Blend flour, sugar and salt in processor. Add butter and shortening and cut in using on/off turns until mixture resembles coarse meal. Add 6 tablespoons ice water and process until moist clumps form, adding more water by teaspoonfuls if dough is dry. Gather into ball, then flatten into a disk. Wrap in plastic and chill 2 hours.
Preheat oven to 400F. Spray your muffin pan with cooking spray. Roll out dough to 1/3 inch thickness. Using a round biscuit cutter, cut out rounds and nestle them into the muffin pan. Crimp edge and dock bottom. Line with aluminum foil and fill with pie weights. Bake with the foil for 20-25 minutes, before removing the foil and weights, returning the shells to the oven for a few minutes (5-8 minutes) to brown.
While the tart shells are baking, make the filling. Heat the butter and the sugar in a large heavy sauté pan until the mixture starts to bubble, turn the heat down and add the diced quince and a dash of cinnamon. Cook until soft and caramelized, about 30 minutes. Remove with a slotted spoon and divide them evenly among the pastry shells.