Heat the oil in a large pot over medium-high heat. Cook the sausages until evenly browned and break into pieces. Stir in the onions, carrots, celery, garlic, basil, rosemary, chilli flakes and sage. Continue cooking 10 minutes, until vegetables are tender.
Mix in tomatoes and cook until heated through. Stir in the stock and beans. Bring to a boil. Reduce heat to low and simmer 20 minutes.
Stir pasta into soup and continue cooking 10 minutes, or until pasta is al dente.