Heat 1 tablespoon of the oil in a large frypan over a moderate heat and brown the shanks all over.

Heat the remaining oil in a saucepan and gently cook the onions, garlic, celery,parsnip and rosemary until the onion is tender but not coloured.

Remove the shanks from the frypan and add them to the vegetables in the saucepan. Pour over the beef stock, season with salt and pepper, simmer covered, for 1 1/2 hours until the meat is falling off the bones.

Set the soup aside to cool. Skim any excess fat off the surface and flake the meat from the shanks, discarding the fat but leaving the bones, if you wish.

Reheat the soup and add the beans and peas and simmer for 20 minutes before serving.