Preheat oven at 170c/150c fan.
Cut the sweet potatoes into thin pieces using mandolin. Insert the pieces between two sheets of kitchen towels and press to dry out the potatoes. Lay out the potato pieces flat on a baking sheet lined with greaseproof paper. Brush the sweet potatoes with olive oil and season with salt and pepper. Bake in the bottom of the oven for 20 min.
