Line two large baking trays and set aside.
Peel the sweet potatoes and cut into 6mm (1/4") chips. You will have some smaller chips from the edges, which is perfectly fine.
Mound the cut chips onto one of the baking trays and drizzle over the olive oil.
Season well with salt and pepper, and toss the chips well to ensure that every piece is well coated in oil.
Spread the chips out over the two baking tray(s), ensuring that they are well spaced on the trays.
Place the trays in the oven and cook the chips for 15 minutes.
Flip the chips with a large spatula, and cook for a further 10 minutes, or until golden brown. Keep an eye on the chips towards the end of the cooking time as they can burn, particularly the smaller pieces from the edge.
I don't normally use specific quantities to make these chips. I work on how hungry I think we will be, the size of the sweet potatoes, whether they are for afternoon tea or a dinner accompaniment, and whether there is dessert. The process is the important part. If you get that right you will end up with great chips.
The cooking time given is for thin chips. If you make thicker chips you will need to increase the cooking time.
Add additional flavour by tossing finely chopped rosemary through the chips before baking, or sprinkling finely grated Parmesan over the chips about five minutes before the end of the cooking time.