"This is an old French recipe that was passed down from my great-grandmother to my mother and to myself and my family. Many people think that this has to do with fish or sea food when they see the name, but it does not have anything to do with fish at all. The name in French is six pates, which translated in English means 6 doughs."
In a Dutch oven, cook meat over medium-low heat until the mixture begins to brown. Mix in onions and celery, and continue cooking for about 5 minutes.
Preheat oven to 350 degrees F (175 degrees C).
Arrange 2 pie crusts in a single layer on the bottom of a large roasting pan. Spread 1/2 of the meat over the pie crusts. Arrange 2 more pie crusts over the meat layer, and then spread remaining meat on top of the pastry. Top with remaining pastry. Press the pastry to the sides of the pan, and poke 8 small holes in the pastry to allow steam to escape.
Bake for 1 hour, or until dough is golden brown and the pie is hot and bubbly.