The potatoes will sit quite happily in the frying pan ready to fry when you are ready. Choose small to medium-sized potatoes as these are easier to boil whole. If the potatoes are thin-skinned there is no need to peel them. If you have leftover cooked potatoes in the fridge, use those.
- Boil the potatoes until just tender, about 20 minutes. Drain, then slice or chunk the potatoes.
- Melt the butter in a large frying pan over a low heat and add the oil when the butter is sizzling. Then add the potatoes, which should sit comfortably in a single layer.
- Fry slowly, shaking the frying pan from time to time. If the potatoes crumble a little that is good, as you will end up with lovely crisp bits. Keep the heat low so not to burn the potatoes. Fry for about 20 minutes until golden and crisp.