In a large resealable plastic bag, combine the flour, salt, pepper, paprika, ginger and allspice; set aside 2 tablespoons. Add meat to bag; seal and toss to coat.
In a large skillet, cook meat and onions in oil over medium-high heat until meat is no longer pink and onions are tender. Gradually stir in reserved flour mixture. Add potatoes and water; bring to a boil. Cook and stir until thickened, 1-2 minutes. Reduce heat; simmer, uncovered, until potatoes are crisp-tender, 20 minutes.
Meanwhile, for pastry, combine flour and salt. Cut in shortening. Gradually add water, tossing with a fork until dough forms a ball.
Divide pastry in half so one ball is slightly larger than the other. On a lightly floured surface, roll out larger ball to fit a 9-in. deep-dish pie plate. Transfer pastry to pie plate. Trim even with edge of plate. Add filling. Roll out remaining pastry to fit top of pie; place over filling. Trim, seal and flute edges. Cut slits in top.
Brush top with egg. Bake at 450° until golden brown, 20-25 minutes. Serve immediately.