In a large bowl, combine flour and salt; cut in shortening until crumbly. Whisk egg, vinegar and water; sprinkle over dry ingredients and toss. If needed, add more water, 1 tablespoon at a time, until dough can be formed into a ball. Divide into four balls. Cover and chill for 30 minutes.
On a lightly floured surface, roll out two balls to fit two 9-in. pie pans. Combine filling ingredients (partially thaw fruit if necessary); spoon into crust. Roll remaining pastry to fit pies; place over filling. Seal and flute edges.
Beat yolk and water; brush over pies. Cut slits in top crust. Bake at 350° for 50-60 minutes or until golden brown.