In a food processor, combine flour, sugar, and salt. Add chilled butter until mixture resembles coarse crumbs. Gradually add ice water until a rough dough forms. Knead gently, shape into a square, wrap in plastic, and chill for at least 10 minutes.

Heat olive oil in a large pot over medium heat. Add diced onion and celery, sauté for 4 minutes. Stir in diced potato, cook for additional 2 minutes, then add ground turkey. Cook until browned, about 5-6 minutes.

Sprinkle flour over mixture and stir to combine, cooking for 1 minute. Gradually pour in chicken stock while stirring until thickened, about 4-5 minutes. Remove from heat and fold in cheese, cranberry sauce, and chives.

Preheat oven to 400°F (200°C). Roll out chilled dough to about ¼ inch thick. Cut out 4-inch squares and press into a greased muffin tin. Fill with turkey mixture, cut more squares for tops, seal edges, and brush with egg.

Bake for 20-25 minutes, until crusts are golden brown. Allow to cool slightly before serving.