If the kidney still has its outer casing of suet fat, then carefully peel it away. Use a sharp knife or scissors to trim away the inner sinew from the interior of the kidney, but take care to leave enough that the kidney nodules stay together

Form the kidney into a cylinder, and wrap it tightly in cling film, as you would for a ballotine. Chill for 4 hours

Cut the chilled kidney into six slices and then remove the clingfilm. Season with salt

Heat the oil in a heavy frying pan and add the kidneys in a single layer. Fry briskly for a few minutes until browned, then turn each of the slices over and fry for another 2–3 minutes. This will take them to a rosy pink

Remove the slices from the pan and rest in a warm spot

Add the butter to the pan and, once foaming, add in the shallot. Turn down the heat and cook gently until softened

Pour in the Madeira and bring to the boil, then reduce by half

Add the veal stock and the mustard. Bring to a good boil and then whisk everything together

Add the cream and parsley then return the sauce to the boil. Check the seasoning and correct if needed. If the sauce needs more body add a knob of butter, then simmer the sauce until the butter has emulsified

Check the seasoning one final time and return the kidneys to the pan along with their juices. These are best served on a good quenelle of pomme purée. Arrange the kidneys on the purée and spoon over the sauce, serving any extra sauce alongside