Directions

1. For the filling, trim your turkey breasts: you want to create a long tube of meat in the middle of your Wellington, similar in shape to a fillet of beef. You can use the trimmings in the stuffing, so don't worry about wastage. Once you have the correct shape, slice a pocket into the breasts deep enough so that the brie and cranberry sauce will stay inside, but don't cut all the way through. Divide the cranberry sauce and brie between the two turkey breasts, then chill while you make the stuffing.
2. For the stuffing, heat the butter in a frying pan and gently cook the leek for about 5 mins. Meanwhile, finely chop the turkey trimmings and add to the pan with the gammon. Cook for about 5 mins, then remove and allow to cool slightly. Mix with the sausagemeat, sage and breadcrumbs, then season.
3. Roll out the first block of pastry on a floured surface to about PS1 thickness: you want a long thin shape that is about 5cm wider than turkey breast width and 5cm longer than length of turkey breasts placed end to end. Gently lift this onto a baking sheet and put the turkey breasts on top, followed by the stuffing. Roll out the second block of pastry, brush the edge of the bottom sheet with egg and lay the top one over. Trim edges to neaten, then crimp together.Can be made up to 1 day in advance and chilled.
4. Heat oven to 200C/180C fan/gas 6. Brush the Wellington with more beaten egg and, with a sharp knife, score a criss-cross pattern, but don't cut all the way through. Cook for 30 mins, then cover with foil and cook for 30-45 mins more. After 1 hr, check that the middle is hot by inserting a skewer for 5 secs - it should feel hot to the touch. Leave to rest for 15 mins, then slice to serve.