Weigh out the potatoes as specified in the recipe.
Slice in half lengthways, then place the halves cut-side down on a chopping board, halve again, then cut each resulting half in two.
You should now have 8 chunky potato wedges. If your potatoes are very big, you might want to halve each wedge once more, but that is entirely up to you.
Pour the vegetable oil into a small bowl, then throw the wedges in, shaking them about until they are covered in oil. If you don't mind getting your fingers greasy, using your hands can help to get even coverage. Sprinkle with salt, pepper, and if you would like your wedges spicy, add a bit of chilli powder or garam masala.
Place the wedges skin-side down on a baking sheet and bake for 20-25 minutes on 220 C (200 fan). Start checking after 15 minutes and take out when brown and puffy.