Heat the butter in a pan. Add the flour, cook briefly; the flour must not take on any colour. Pour in the milk and stock all at once, bring to the boil while stirring, reduce the heat. Stir in the saffron, season, simmer over a medium heat for approx. 10 mins., stirring occasionally until the sauce is thick and creamy. Stir in the parmesan, set aside the sauce.
Remove the bottom 3-4 rows of leaves from the artichokes and trim the remaining tips by approx. half, remove the fuzzy centres, cut into six pieces. Cook the artichokes in boiling salted water for approx. 2 mins., add the tagliatelle and cook for approx. 2 mins., drain and set aside approx. 100 ml of the cooking water. Place the tagliatelle, artichokes and reserved cooking water in the same pan, add the cream along with the sauce, mix well. Sprinkle with parsley.