1 Bring pasta to a boil in plenty of salted water until al dente. Drain and rinse with cold water, drain again.
2 While the pasta is cooking, rinse chicken breast fillets, pat dry and cut into 1 cm (approximately 1/2-inch) cubes.
3 Pour stock into a pot and add diced chicken. Bring to a boil over medium heat and cook for 5 minutes.
4 Using a slotted spoon, remove diced chicken from liquid. Pour the stock through a fine sieve and into a 2nd pot.
5 Rinse carrots and zucchini. Trim and peel carrots. Slice carrots and zucchini into thin strips.
6 Rinse and peel fennel, reserving the fronds. Halve bulb and slice lengthwise into thin strips.
7 Bring broth to a boil. Add carrots, zucchini, fennel and saffron. Cook for 2 minutes over medium heat.
8 Add chicken cubes and cook for another 3 minutes. Season with salt and pepper.
9 Add the warm pasta to the boiling broth. Ladle soup into bowls. Chop fennel fronds, sprinkle on the soup and serve.