I love roast potatoes - it's that gorgeous crispy exterior contrasting with the soft, fluffy interior that get me every time!
Desirée, King Edwards and Yukon Gold are options, but for me it has to be a Maris Piper. There's something about them that gives the best (IMHO) crisp and fluffy combination.
I always start the parboiling process with cold water, rather than boiling, as it helps to ensure even cooking of the potatoes. They are cooked for at least 9 minutes, to ensure maximum fluffiness!
In terms of oil, then it has to be a neutral option like vegetable or rapeseed - both let the flavour of the potato shine through. It' s important to get the oil really hot before you add the potatoes, and if you want all round crispiness then turning during the cooking process is key!
Maris Piper
8 tablespoons of vegetable oil
3-5 fresh thyme sprigs
Sea salt