Scotch broth soup
Put the lamb and 1.8 litres/3pt water in a large heavy saucepan, and bring to the boil. Skim off any scum from the surface, then stir in the onion, pearl barley and bouquet garni. Bring the soup back to the boil, part-cover the pan and simmer gently for 1 hour.
Add the remaining vegetables, and season with salt and pepper. Bring to the boil again, part-cover and simmer for 35 minutes.
Use kitchen paper to skim surplus fat from the top of the soup. Discard the bouquet garni and serve hot.