In a food processor, combine all-purpose flour, granulated sugar, and kosher salt. Add cubed chilled unsalted butter and pulse until it resembles coarse crumbs. Gradually add ice water, pulsing until the dough comes together. Wrap in plastic wrap and chill in the refrigerator for 10 minutes.

In a large skillet, heat extra-virgin olive oil over medium heat. Add chopped yellow onion, diced celery stalk, and diced russet potato, cooking until tender, about 5-7 minutes. Stir in ground dark meat turkey, seasoning with salt and pepper, and cook until browned. Mix in flour, then gradually add chicken stock while stirring until thickened, approximately 3-5 minutes. Fold in shredded Havarti cheese, canned cranberry sauce, and diced chives.

Preheat oven to 400°F (200°C). Roll out the chilled dough on a floured surface to about ¼-inch thickness. Cut into 4-inch squares, fitting them into a greased muffin tin. Spoon turkey and cranberry filling into each crust, then cover with another square of dough. Press edges to seal, and crimp with a fork. Brush tops with a beaten egg.

Place muffin tin in the preheated oven and bake for 20-25 minutes, or until tops are golden brown and filling is bubbling. Remove from oven and let cool slightly.

Carefully lift pot pies from muffin tin and serve warm or at room temperature.