For pastry (can also purchase ready made crust):
1 1/2 c. all-purpose flour
2 tsp salt
8 T. butter, cold
1/4 c. ice water
1 1/2 c. chicken broth
1 lb. boned, skinless chicken breast cut into 1-inch cubes (thighs if prefer dark meat)
4 T. butter
1 small onion, finely chopped
3 T all-purpose flour
1 c. coarsely chopped carrot
3/4 c. celery
3/4 c. fresh or frozen defrosted peas
1 T. finely chopped parsley
2 tsp. finely chopped chives
1 tsp dried tarragon or sage
salt and freshly ground black pepper, to taste
1 egg yolk, ligtly beaten with 1 T. milk
To make pastry:
Sift together flour and salt, and place in a food processor. Add butter and process for 7 - 8 seconds (it is not necessary for butter to be fully incorporated). Add water and process for 2-3 seconds more, until dough starts to hold together on the blade. Do not overprocess or dough will be tough.
Turn dough out onto a floured work surface. Using the heel of your hand, spread dough out 6 - 8 inches in front of you, a little at a time, to finish incorporating the butter. Make dough into a disk ball shape, wrap in plastic wrap and chill for at least 2 hours.
Pour chicken broth into a saucepan and bring to a boil. Add chicken pieces, lower heat, and simmer for 10 - 15 minutes, until just tender. Remove chicken with a slotted spoon and set aside. Keep chicken broth warm.
Heat butter in a medium-size saucepan over low heat. Add onion and cook for 4 - 5 minutes, until softened. Sprinkle flour over onion an stir to combine. Continue to cook for 2 more minutes, stirring continuously.
Slowly add warm chicken broth to onion mixture, stirring until sauce thickens. Add carrots, simmer for 5 minutes. Add peas, reserved chicken and herbs; season with salt and pepper to taste. Pour filling into a deep 2-quart pie dish.
For a healthier version without the butter, just add the onions, carrots, and celery to the broth and simmer for a few minutes. Then take the 3 T. of flour and put it in a small jar with some COLD water or broth and shake well until blended. Pour that into the simmering chicken broth and then add the peas and other ingredients from there.
Preheat oven to 350º F.
Finish off pastry: If you are making the pastry from scratch, roll refrigerated dough out on a floured surface to make a 1/8 in. thick circle that extends out two inches beyond the edge of the pie dish. Place the circle over the filled pie dish, trim, crimp edges, and make several slits in the top to allow steam to escape. You can also cook it in any similar sized casserole dish and adjust the shape of the crust. Brush surface with egg yolk wash.
Place pie on a baking sheet and bake for 30 - 35 minutes or until the pastry is golden.