Wash the meat in cold water and, if necessary, soak overnight to remove any excess salt.

Place the meat in a large saucepan, cover with cold water and bring to the boil. Cover with a lid or foil and simmer very gently for 35 minutes per lb (450g) plus an extra 35 minutes.

Peel the carrots and onions (leave them whole) and add them to the pan for the last hour of the meat's cooking time.

Lift the meat onto a serving dish, remove the vegetables with a slotted spoon and arrange around the meat.

Melt the butter in a saucepan, add the flour and cook for 2 minutes.

Stir in the milk and 1/2 pt (300ml) of cooking liquor and bring the sauce to the boil, stirring constantly. Simmer for 2 minutes to thicken.

Blend together the mustard, sugar and vinegar and stir into the sauce. Cook for 1 minute, then add salt and pepper to taste.