1. Either peeled or un-peeled, cut the potatoes into big chips (one large potato per person should be sufficient, but adjust according to level of anticipated hunger!) Both ordinary and sweet potatoes can be done together if you want - both take the same time to cook. 2. Put the chips into a large pot of salted cold water, and bring them to the boil. As soon as the chips have come to the boil, drain them, and tip them into a large bowl. 3. Sprinkle the chips with enough Olive Oil to coat them well, and toss them around with your hands or a wooden spoon until they are well covered in oil. (Hands are best for this job - let them cool for a minute or two if you need to). At this point you can add any extra ingredients you want - not that you have to. A fairly basic but very tasty option is simply to add plenty of freshly milled pepper and plenty of coarse salt (the Maldon stuff works well). Other options are pesto, finely grated cheese, herbs (I imagine thyme would be quite tasty), spices (e.g. chilli powder for hot and spicy, but maybe just a bit of ginger powder and cumin for curry flavour chips, etc, etc.), minced garlic, soy sauce, ....anything at all you want. Whatever you add, mix it all through so all the chips are covered evenly. 4. Spread the chips evenly on a baking tray (use more than one if you need to - best not to have the chips piled up on top of each other) and stick them in a hot (200c) oven for 20 minutes or so. Give them a shake or a stir halfway through if you like.