- To make the pastry; combine the flour, salt and mustard powder in a large bowl. Grate the butter over the bowl and use a round ended knife to mix it into the flour. Adding a little water begin to mix the dough using the knife. Add further water to bring the pastry together with your fingers. Roll gently into a ball, wrap and chill for 30 minutes.
- Slit the skins of the sausages and squeeze the meat into a bowl. Discard the skins. Add the bacon, lemon zest, nutmeg, herbs and pepper and mix together using wet hands.
- Preheat the oven to fan 200C/220C/gas mark 7. Dust the work surface with flour and roll out the pastry to a rectangle approximately 20cmx40cm then divide in 2 lengthways, so you have 2 strips 10cm x 40cm. Divide the sausage meat into 2 lengths to fit the pastry and place slightly off centre. Brush the egg wash along one edge and roll the pastry over the meat. Press the edges together with the prongs of a fork to seal. Cut the lengths into 6, place on a lightly greased baking tray and brush all over with the egg wash. Prick the top of the rolls with a fork to let out the steam whilst cooking and bake for 25-30 minutes until golden and puffed up. Tempting though it is to eat them straight from the oven, cool slightly before devouring and if there are any left store in an airtight container for up to 3 days in the fridge.