• Preheat oven to 400ºF.

For the Filling

• Heat a large pan over medium heat. Add the butter, onions, and celery. Cook until soft and translucent, about 5 minutes. Add the garlic, mushroom powder, and thyme and cook until fragrant, about 1 minute more. Add the chicken stock and sherry vinegar and cook until little to no liquid remains, about 3 minutes. Add in the chicken and cook, stirring often almost just cooked through, about 5 minutes. Finally, add the cream cheese, cream, gelatin, and glucomann powder. Cook stirring until thickened and the liquid is smooth and the chicken is only just cooked through (a bit undercooked is better than overcooked as it will bake briefly), about 3-5 more minutes. Set aside off heat.
• For the Dough:
• Add mozzarella and cream cheese to a microwave safe bowl and microwave on full power for 1 minute. Stir then continue to microwave for another 30 seconds to 1 minute, or until cheese is fully melted. Add in remaining crust ingredients, being sure to add only half the beaten egg (remaining half will be used to brush the tops of the dough) and stir until evenly combined.
• Shape the dough into a ball and then press between two pieces of parchment paper. Use a rolling pin to roll the dough to 1/4-1/8 inch thick. Remove the top piece of parchment paper and using the individual baking dishes you will bake the pies in as a stencil, trim the dough just slightly larger than the tops of the baking dishes. You will have extra dough (about half will not be used).

To Finish

• Transfer the slightly cooled chicken filling into the individual serving containers. Top with dough rounds, pressing the dough onto the sides of the baking dish to seal well and pushing any excess down into the dish.
• Cut three slits in the top of the crust for steam to escape. Brush the tops with remaining egg and bake for 10 min at 400ºF, or until golden. Let cool slightly before serving.