Place chicken, salt, pepper, thyme, and sage in a large Dutch oven; add water to cover. Bring to a boil; cover and simmer 1 hour or until tender. Remove chicken, reserving 1 cup broth; cool chicken. Remove chicken from bone, and cut into bite-size pieces.
Line a 2-quart baking dish with two-thirds of pastry. Place chicken in pastry shell.
Melt 2 tablespoons butter in a medium saucepan; add flour, stirring until smooth. Cook 1 minute, stirring constantly. Gradually stir in broth; cook over medium heat, stirring constantly, until thickened and bubbly. Pour sauce evenly over chicken.
Place ham pieces over chicken mixture, and dot with remaining butter. Top with remaining pastry. Trim edges of pastry; seal and crimp edges. Cut slits to allow steam to escape. Decorate with pastry cutouts, if desired. Bake at 400° for 40 minutes or until crust is golden brown.