Line a 9-in. pie plate with pastry; flute edges. Line pastry shell with a double thickness of heavy-duty foil. Bake at 450° for 5 minutes. Remove foil; bake 5 minutes longer. Cool on a wire rack. Reduce heat to 350°.
In a large bowl, combine the sugar, flour and salt. Stir in the eggs, butter, mincemeat and walnuts until blended. Pour into crust.
Bake for 40-45 minutes or until a knife inserted in the center comes out clean. Cover edges with foil during the last 15 minutes to prevent overbrowning if necessary. Cool on a wire rack.