In a food processor, pulse together the all-purpose flour, granulated sugar, and kosher salt. Add chilled, cubed unsalted butter and pulse until the mixture resembles coarse crumbles. Gradually add ice water, just until the dough holds together. Chill the dough in the refrigerator while you prep the filling.

Heat extra-virgin olive oil in a large skillet over medium heat. Sauté chopped yellow onion and diced celery stalk for about 5 minutes until softened. Add peeled and diced russet potato, cooking until tender. Stir in ground dark meat turkey, then season with freshly ground black pepper before adding all-purpose flour, followed by chicken stock. Cook until thickened.

Remove the skillet from heat and fold in shredded Havarti cheese, canned chunky cranberry sauce, and diced chives into your turkey mixture. Mix until well combined, then allow the filling to cool slightly.

Preheat oven to 400ºF. On a floured surface, roll out half of the chilled dough to about ⅛ inch thick. Cut squares and press them into the cups of a greased muffin tin. Fill each with the turkey and cranberry mixture, then roll out the remaining dough, cutting into squares to cover the tops. Press edges to seal and brush the tops with a beaten egg.

Place the assembled pot pies in the preheated oven and bake for 20-25 minutes until the crust turns golden brown. Let cool for a few minutes before serving warm.