In Dutch oven, saute the bacon until wilted but not browned
Add onion, peppers, and celery and saute until golden.
Sprinkle chicken with flour, salt, pepper, and sage. Add to the pan and brown on all sides.
Deglaze the pan with Sherry.
Add mushroom broth, potatoes, and carrots. Simmer until the vegetables are soft.
Add cream of chicken soup and stir well.
Remove from heat and while cooling, make a butter pie crust: Blend together flour, sugar, and salt. Cut in small pieces of butter using a pastry blender. Add ice water, 1 tablespoon at a time until dough pulls from the side of the bowl.
Chill the dough in the refrigerator. If desired, chill the filling overnight.
Preheat the oven to 350. Place filling in a pie dish. Roll out the dough, trim, and place on top of the filling.