Heat the oil in a large pan and fry the sausages until brown all over. Pour in the hot chicken stock and simmer with a lid on for 10 mins. Add the pasta to the pan, mix well and bring to the boil. Stir in the carrots and onions, cook for 5 mins, then add the celery and beans, and cook for a further 4 mins. Check that the pasta is cooked – if not, cook for a few minutes longer. Finally, stir in chopped parsley, season, and serve in large bowls.