This is the traditional no-vegetable chicken pie that Kate – and many others prefer.
Simmer the chicken in a large kettle with celery and salt and pepper to taste. When chicken is tender, remove it from the broth. Save the broth, discarding the celery stalk. Bone the chicken and separate into medium-sized pieces; put the pieces in the bottom of a large casserole dish. Using extra flour to thicken the reserved broth, make about a quart of gravy; while still hot, pour enough gravy over the chicken to cover. Combine the remaining 2 cups of flour, baking powder, baking soda, sugar, and salt in a bowl. Cut in the shortening and add enough milk to make a soft biscuit dough. Roll out the dough and place it over the chicken and gravy. Cut a hole in the center of the dough and insert an inverted custard cup, pressing it down into the pie (this will vent the pie and help it cook evenly). Place the pie in a preheated 425 degrees F. oven; immediately turn heat down to 350 degrees F and bake for 45 to 50 minutes, until biscuit is golden. Serve with extra gravy nearby.