Clean, wash and chop the fennel, celery and spring onions. Peel and dice the garlic. Drain the beans.
Heat the oil in a large saucepan. Roast the fennel, celery, onions and garlic vigorously, turning frequently. Deglaze with 1 liter of water, add the beans, sprinkle with the vegetable stock and simmer the stew over low heat for 10 minutes. Add the pasta and continue cooking until the pasta is cooked through.