Cast Iron Chicken Pot Pie with Cheddar Drop Biscuits

I found this recipe on Tasty Kitchen an it was submitted by Alaska from Scratch.  I have always loved pot pies but hated to make the crusts so this was an easy fix since it doesn't have a crust and so that probably makes it not a real pot pie.  I have made this several times and we really like it.   It is also very easy to make as I usually use my bottled chicken.  Clint took the picture.

Chicken pot pie with Cheddar Drop Biscuits

For the filling:
2 TB. butter
1 onion finely chopped  (I used dried as I didn't have an onion)
1/4 C flour
2 C chicken broth
1 C Milk
2 C cooked chicken (light and dark meat, leftovers, or a rotisserie chicken)
1- 3/4 C frozen peas and carrot mixture
1 TB fresh parsley chopped, (I didn't use this)
Salt and pepper to taste

For the Biscuits
2 C flour
1 TB baking Powder
1/4 tsp baking soda
1/2 tsp salt
2 tsp. sugar
6 TB cold butter cut into 1/2 " pieces
1 C medium cheddar cheese, grated, (I used mild as that is all I had)
1- 1/4 C buttermilk
Pepper

Heat a 12 inch cast iron skillet (I am sure you can use any skillet that will go into the oven) over medium heat, add butter and then onions, cooking till translucent.  Sprinkle in flour, stirring constantly and cook for 1 to 2 minutes.  Pour in chicken broth and the milk, stirring till combined.  Turn up the heat and bring to a boil and then reduce heat to simmer for about 10 minutes, stirring as mixture thickens.   Add chicken, vegetables and seasonings.
Preheat oven to 425 degrees.
For the biscuits, stir together the dry ingredients.  Cut in the butter with a pastry blender or use your fingers until the mixture is crumbly.   Stir in cheese, followed by the buttermilk.   Stir just until it comes together and forms a thick sticky dough.   Do not over stir.  Drop the biscuit dough, about 1/4 Cup
size dollops on the top of the pot pie filling.   Sprinkle the biscuits with black pepper, (I didn't do this but it would be good).  Place skillet in preheated oven and bake for 20 minutes or until the biscuits are golden.