Directions

1. Preheat the oven to 190°C/375°F/Gas 5. Get a large roasting tin and rack and two large sheets of foil, one of them buttered.
   
   To make the filling, add the gammon pieces to a pan and dry fry for 3-4 minutes. Add the leeks and cook for about 5 minutes, stirring occasionally until the leeks wilt. Season and set aside.
   
   To make the suet pastry, mix together the flour and suet in a bowl, add the parsley and seasoning. Stir in just over 150ml (1⁄4 pint) cold water, with a round-bladed knife, to make a soft dough. Knead very lightly on a floured surface and roll out to a 23cm (9in) square.
   
   Dip your finger in water and dampen all around the pastry edge. Spread the bacon and leek mixture over, leaving the border uncovered. Roll up the pastry like a Swiss roll and seal the ends. Place this on the buttered sheet of foil. Bring the foil up around the roll in a baggy parcel so there is room for the pastry to rise a little. Seal the ends and top well.
   
   Put the parcel on the rack in the roasting tin. Pour boiling water round to half fill the tin then quickly cover the whole tin with the other sheet of foil, sealing it well to retain the steam. Carefully carry the tin to the oven and bake for 2 hours.
   
   Take out and leave for 5 minutes before unwrapping - watch out, it will still be hot. Place on a serving platter, slice and serve with more vegetables.