Peel the sweet potato. Pre-heat your oven to 200°C.
Cut the potato into very thin slices. If you have a mandolin it’s perfect for the job, otherwise use a very sharp knife. It helps to have a flat side of the potato facing the chopping board, so cut a small amount off to get this if required.
Place the slices in a large bowl and add the remaining ingredients. Mix well.
Place the slices evenly on a large grill-pan (i.e. with a wire-rack) or a baking tray lined with greaseproof paper. Don’t overlap the slices. Pour the oil/spice mix over the slices.