Method

• step 1

  Melt the butter in a pan then gently fry the leeks for 5 mins until softened. Add the chicken and cook for 10 mins until opaque, then sprinkle over the flour and cook for 3 mins, stirring. Gradually stir in the stock, then simmer for 5 mins. Stir in the cream, pecorino and 1-2 tsp of freshly ground black pepper, depending on how peppery you want it. Taste and season with a little salt if needed.

• step 2

  Tip into a 23cm pie dish and leave to cool, then chill for 30 mins or until you want to bake it.

• step 3

  Heat the oven to 200C/180C fan/gas 6. Unroll the pastry and cut into 4cm x 6cm rectangles. Brush each piece with egg, then use to cover the surface of the pie, patchworking and overlapping so there are no gaps. Chill for 20 mins then glaze again. Make a steam hole in the middle of the pie with a small sharp knife. Bake for 40 mins until the pastry is crisp, puffed and golden.