Chicken, Spring onion and Tarragon Pie

I have had this recipe for awhile to try but because of the timing haven't had a chance to try it. I preplaned dinner this week so I could get the timing right and finally try it. It is definitely a recipe that needs forward planning. It is recipe that you need to either do on the weekend or over 2 nights. That being said, once the filling os made on the first night, assembly doesn't take long the next day. The recipe makes 6-8 individual pies. So firstly to prepare the chicken. Preheat the oven to 160 degrees Celcius. In a large frying pan brown off the chicken, in batches. Careful not to over crowd the pan. It should take around 4-5 minutes. Transfer the chicken to a roasting pan. Remove the excess fat from the pan and add the spring onions, celery and leek. Saute until tender 3-4 minutes, then deglaze the pan with the vermouth (you can use white wine if you prefer.) Allow to simmer for a further 3 minutes. Add the stock and tarragon sprigs and bring to the boil. Seas...