Put the pork into a roasting pan with 1 cup water, white wine, vinegar, bayleaves, lemon zest, salt and pepper.
Bake in a moderate oven. Baste from time to time until the pork is tender. Take from the pan, thicken the sauce with a flour and water paste, add the madeira and strain.
Slice the pork and serve with the sauce poured over it.
Tom make a crisp crust, remove the pork from the pan when it is tender and leave to get cold. Brush the top with beaten egg yolk, coat with breadcrumbs, moisten with gravy and return to the oven. Continue roasting and basting until you have a crust half an inch thick.