Being lazy, and lacking dexterity, I am always keen to simplify kitchen tasks. Roasting potatoes is scarcely the most bothersome procedure; but the bit when you have to heat the oil in the roasting tin, tip in the potatoes, turn them all over to coat them, and then arrange them so that they are not in a heap -- that is a nuisance.
The theory is that the oil should be hot so that a crust, impermeable to further oil, forms quickly. But is it true that this is the only way to ensure a crispy, and not excessively oily, result? If you could use cold oil, you would simplify the job.
Peel the potatoes, cut them into whatever shapes you like, and drop them into cold, unsalted water in a saucepan. Bring the pan to a boil; meanwhile, put a roasting tin into the top of a gas mark 6/200 C oven. Simmer the potatoes for three to five minutes, and drain. Return the potatoes to the hot pan; perhaps over a gentle heat, stir them about to get rid of the surface moisture. Now add your oil -- for this experiment, I used groundnut. Use just enough oil to coat the potatoes, and turn them about in it. Take the roasting tin out of the oven, tip in the potatoes, spread them out, and return to the oven for 50 minutes to an hour, turning once.
These potatoes were just as good as ones started in hot oil. For more on the subject, look here, here or here.