Heat oven to 375°F. Combine baking mix and salt in large bowl. Cut in butter and shortening with pastry blender or fork until mixture resembles coarse crumbs.
Combine egg, water and vinegar in separate bowl; beat with fork until mixed. Add egg mixture to baking mix mixture; stir just until combined and can be shaped into ball.
Dust 15-inch length of wax paper or parchment paper with baking mix. Place pastry ball on paper; lightly sprinkle with baking mix. Top with another sheet of wax paper or parchment paper. Roll out pastry into 12-inch circle.
Transfer pastry to ungreased 9-inch pie pan, pressing firmly against bottom and sides and sealing any cracks. Crimp edges. Prick bottom and sides of pie crust with fork.
Bake 13 to 15 minutes or until edges are lightly browned. Cool completely.
Note: Always read labels of each ingredient to ensure that they are gluten-free prior to use.