Wash the barley in cold water and drain, then place in a pan, cover with stock and simmer gently for one hour.
Heat the olive oil in a pan. Add the onion and garlic and sauté for five minutes on a low heat. Add to the pan with the cooked barley; also add the carrot, parsnip, swede and turnip and simmer for a further 15 minutes. Add the leeks, celery and spinach and simmer for a further 10 minutes. Finally add the peas and simmer for a further five minutes.
Garnish with a sprig of parsley and serve.