Icelandic smoked lamb with white sauce (Hangikjöt)

1. Put the smoked lamb in a large pot with enough cold water to cover and bring slowly to the boil.

2. Cover and simmer over low heat for about 2 hours, then leave it to cool to lukewarm in the cooking liquid so it stays juicy.

3. Meanwhile, for the sauce, melt the butter, stir in the flour and cook for 1-2 minutes without letting it brown.

4. Gradually whisk in the milk and simmer for 5 minutes until thick and creamy; season with the sugar and salt.

5. Cook the peas in salted water for 3 minutes and drain.

6. Slice the meat thinly and serve warm or cold with the white sauce, peas, boiled potatoes and pickled beetroot.

Tip: Hangikjöt, "hung meat", is an essential part of Icelandic Christmas; it is traditionally smoked over birch or dried sheep dung, which gives it an unusually deep, smoky flavour. Outside Iceland use smoked leg of lamb or good-quality smoked ham; if it is very salty, soak it overnight in cold water before cooking. Leftovers are great cold on buttered rye bread.