for the Crust
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 tart filling:
3 large eggs
2/3 cup packed dark brown sugar
2/3 cup light corn syrup
1/2 stick unsalted butter, melted and cooled
1/2 teaspoon salt
1 teaspoon vanilla
1 1/4 cups chopped fresh cranberries
1 cup chopped walnuts
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; divide into 2 pieces. Flatten each into disk. Wrap each in plastic; chill 2 hours.
Preheat oven to 425F.
Roll out 1 dough disk on floured surface to 13 inch diameter circle. Transfer to 9-inch-diameter glass pie dish. Fold edge under, forming high-standing rim; crimp. Line shell with foil and fill with pie weights. Bake until pastry is set and pale golden on rim, about 15 minutes. Carefully remove foil and weights and bake shell until pale golden all over, 5 to 10 minutes more. Transfer shell in pan to a rack.
Make filling: Reduce oven temperature to 350F. Whisk together eggs, brown sugar, corn syrup, butter, salt, and vanilla in a bowl until smooth, then stir in cranberries and walnuts. Pour filling into shell and bake tart until filling is set and golden, 40 to 45 minutes. (If pastry edge darkens before tart is done, cover edge with a pie shield or foil.) Cool completely in pan on rack.