Boil chicken in water and salt. Chop chicken and reserve 2 cups of broth. Sauté vegetables in butter for about 10 minutes. Add flour to butter and stir till cooked. Add broth and milk, stirring till thick and bubbly. Add chicken and vegetables, and pour into casserole dish. Roll out pie crust and place over the top. Cut slits to allow steam to escape. Bake at 180 C for 30 minutes. Cover with foil and bake for another 20 minutes. Pie crust: (1 Oval) 1 1/3 c flour ½ t salt ½ c margarine 3-4 T cold water