Leeks with Rosemary Mayonnaise

Ingredients
ROSEMARY MAYONNAISE
 * 8 leeks
 * 250 ml salted chicken stock
 * 2 bay leaves
 * 2 x 7,5 cm sprigs fresh rosemary
 * paprika to garnish
 * 1 egg
 * 20 ml lemon juice
 * 2 ml salt
 * 200 ml oil
 * 5 ml sugar
 * 10 ml Dijon mustard
 * 50 ml sour cream

Directions

 * 1) Cut off roots and most of the tops of the leeks, leaving not more than 3 cm of the green leaves. Remove outside layer. Make a shallow cut down length of leek so that the layers may be opened out slightly. Wash very well to remove grit. Put stock, bay leaves and rosemary sprigs into large frying pan with a lid. Add leeks, bring to boil and simmer, covered, for about 7 - 10 minutes or until just cooked. Cool in liquid, then drain and chill, reserving rosemary.
 * 2) To make the mayonnaise, place egg, lemon juice, salt, 25 ml oil, sugar and mustard into a blender. Strip needles from the reserved cooked rosemary sprigs and add. Blend until well mixed, then with motor running, add remaining oil in a slow, steady stream. Tip into small bowl, stir in sour cream, cover and chill for at least 2 hours.
 * 3) To serve, arrange chilled leeks on serving plates - 2 each should be enough, depending on size. Spoon some mayonnaise down the centre of each serving, and dust with paprika.