Boil the whole sweet potatoes in salted water for 15 minutes. Simmer until cooked and drain well. When they have cooled down a little so you can touch them, cut them into 0.5mm thick slices. If you do not want to pre-cook them, you can also cut them into thinner slices and cook them on the 800°C Steak Grill When cutting them extra thin you will get crunchy crisps.
Combine the spices in a bowl. Add the sweet potato slices and mix everything well. Add olive oil and rub the sweet potato slices until they are covered evenly with olive oil and the spice blend.
Place the marinated sweet potatoes in a fireproof bowl. Preheat your Otto Grill and grill the sweet potatoes at little temperature and Meat-O-Meter level 3 until they are golden and crispy. Occasionally turn so that they are grilled from all sides.