i never par boil hasslebacks or peel them, they still only take 45 minutes and come out lovely and crispy round the edge if you give them a good shake of salt before cooking.
a quick and healthier way of doing dauphinoise potatoes is to turn the oven on, thinly slice the potaotes into a shallow dish, almost cover them with semi skimmed milk and a good sprinkling of salt and garlic granules. by the time you've done that, the oven will be piping hot so shove the potaotes in for 45 minutes.