For filling, stir together fruit bits, ham, walnuts, and cheese in a mixing bowl.
Unfold pie crusts on a lightly floured surface according to package directions. Transfer one crust to a large ungreased cookie sheet. Sprinkle filling evenly over crust to about 1 inch of the edge. Brush edge with milk; top with second crust. Flute edge of pastry or press with fork to seal. Cut slits or make small cutouts in top pastry to allow steam to escape. Brush top with milk; sprinkle with poppy seeds.
Bake in a 425 degree F oven for 12 to 15 minutes or until golden. Cool slightly on a wire rack. Cut into wedges, and serve warm. Makes 16 servings.