I do them completely differently, and it was my late MIL's way and they always turn out very yummy. No parboiling involved.Use any potatoes at all.
Cut them however you like, large, in half lengthways or in quarters, place them in the pan ,add cold water about an inch of water, add whatever fat you like to use ( not oil) a light sprinkle of sea salt over them and put in a hot oven, turn half way through and baste,and more fat if needed at the half way stage.Takes an hour and a half. They are golden and delicious.MIL was a chef.When I say an inch of water, I mean the whole pan is full of water but the depth is an inch.