Put Spry into mixing bowl. Add boiling water and milk. Beat mixture with a fork until smooth and thick. Sift flour and salt onto mixture. Stir with round the bowl strokes, until dough clings together and cleans the bowl. Lightly form dough into 2 smooth balls. Place dough on lightly floured surface. Flatten slightly. Roll out to form circle 1/8th inch thick. Ease dough into 9" pie pan; trim even with outer edge of pan. Roll out remaining dough. Lay over filled pie shell. Trim about 1/2" beyond edge of pan; fold under bottom crust. Seal by fluting edge with fingers or fork.