Preheat oven to 400° F.

Biscuits:  Combine dry ingredients in bowl.  Cut in the cold butter until resembles small peas.  Slowly add 3/4 Cup of milk and mix with fork until dough is just slightly sticky.  Use more milk if needed.  Remove dough from bowl and fold over 10 times on floured surface.  Flatten the the dough using hands until about 1/2 inch thick.  Cut biscuits using biscuit cutter.

Filling: Saute onion in 2 Tablespoons of butter over medium heat until translucent.  Add remaining butter until melted.   Add the flour and stir until paste forms.  Slowly add the chicken broth and mix.  Let simmer until thickened.  Add evaporated milk, sherry, salt and pepper and combine.  Let simmer to fully thicken and remove from heat.  Add chicken and vegetables.

Bake: Top with prepared biscuits and bake for 30-40 minutes in a preheated 400˚F oven.  Serve warm.