Globe artichoke with Dijon vinaigrette

1) Rub each artichoke with half a lemon.
2) Bring a pan of salted water to the boil and add the juice of the lemon.
3) Put the artichokes into the water and boil uncovered for 25 to 30 minutes, until the outer leaves are easily detached.
4) Remove from the water, turn upside down and drain well.
5) Meanwhile to make the vinaigrette, combine the remaining ingredients in a lidded-jar.Shake well to make a thick dressing, season to taste.
6) To eat, remove one leaf at a time and dip into the vinaigrette pulling off the tender part of the leaf. The leaves will get more and more tender until you reach the choke.