nama shoyu (raw soy sauce)
1) Slice yam using vegetable peeler for very thin slices
2) Soak slices in water, water with salt, nama shoyu with water, or toss with oil.
3) Marinate for 1 hour
4) Dehydrate for 4-6 hours
Tip: Also try lemon juice, sans marinade, salting the marinated slices, etc. The sky's the limit! I liked the nama shoyu ones best. The oil-tossed slices took longer to dry. The water-based slices curled up a lot more.