Preparation

Preheat oven to 375 degrees.
In a frying pan over medium heat, melt the butter.
Add the onion and cook for 10 minutes. Then add the salt, pepper, flour and herbs and cook for 3 to 4 minutes.
Pour in the chicken stock and bring to a boil. Reduce to low heat and add the chicken, then simmer until the stew has thickened slightly and the chicken has cooked, about 15 minutes.
Remove the chicken, add the milk, then cook for an additional 4 minutes. Remove the pan from the heat and split the sauce in half.
Shred the chicken.
To one half of the sauce add the potatoes, peas and shredded chicken. Season with more salt and pepper, if desired, and then place into the fridge. Set the remaining half aside until needed.
Cut 2-inch circles from a sheet of puff pastry and lay a spoonful of the stew on top. Cover with a second circle of pastry and press the edges together with a fork to secure. Repeat until all of the pastry and filling is used up.
Brush pastry pie with egg wash, sprinkle with black pepper and salt and place in the oven for 20 to 25 minutes until puffed up and golden.
Serve immediately with sautéed greens and the remaining gravy heated up on the side.