Boil the potatoes in salted water until
tender, about 15 mins. Drain well in a
colander and steam dry for 5-10 mins.
Make the salad cream by mixing the
flour, sugar, mustard powder and some
seasoning in a bowl, then beat in the
eggs and white wine vinegar. Place
the bowl over a pan of simmering water,
making sure the base does not touch
the water, and stir continuously until it
thickens enough to coat the back of
a spoon, about 5-10 mins.
Remove from the heat and cool.
Add the cream and lemon juice to
taste. Cover and chill until you are
ready to dress the potatoes.
Pick over the frisée, discarding any
damaged leaves, then tear into bite-sized
pieces. Toss the potatoes in the salad
cream along with most of the chives.
Arrange the frisée on a platter or in a
large bowl. Spoon over the potatoes
and scatter with the rest of the chives.