Boil and shred chicken. Set aside.
Dice alliums and sauté over medium heat until softened.
Add butter and flour and cook for 1 minute.
Add chicken stock and heat until simmering.
Add remaining vegetables, shredded chicken, and double cream. Cook until spinach is wilted and everything is incorporated.
Remove from pan and cool completely.
Once filling is cooled, cut pastry sheet in half and fill, fluting one of the halves and the edges once joined.
Brush with egg wash.
Bake in a preheated oven at 400°F / 200°C for 25-30 minutes or until golden brown
