Heat the last tablespoon of
oil in the same frying pan over high heat. Add the
onion and sprinkle with a little
salt.
Cook rapidly, stirring continuously, until the
onion starts to take on some color. Add the
lamb and
rosemary. Continue stirring until the
lamb is just browned. Pour the contents of the frying pan into a strainer set over a bowl.
Place both in the refrigerator to
cool for a while.