Melt butter on medium heat on a large skillet and sauté the onion & celery til clear.
Combine the diced chicken in with the sautéed veggies.
Lower heat to med/low and add the soup mix while stirring.
Slowly add the milk and continue stirring until thickened.
For the crust:
Between two sheets of Saran Wrap, roll out one biscuit at a time until flattened and rolled out to about 6” around.
Use one to line the bottom of the tart/quiche pans.
Use one biscuit crust to line the bottom of the tart/quiche pan.
Spoon chicken mixture into the individual pans and sprinkle with a little cheese then place second biscuit as the top.
Poke holes (using a fork) in the tops for steam release.
Place on a cookie sheet or baking pan.
Bake in 350 for about 20-30 minutes or until crust is evenly browned and baked all the way.