A nested set is a group of bowls that have all been cored from one log section. You can watch unique grain features flow through the set for a truly one of a kind collection. Even in the niche world of hand turned bowls, nested sets like this are a rarity.
Finished with Tung Oil, which is food safe once cured, but I would never recommend a natural edge bowl be used for food. The bark would be impossible to clean and would eventually break off.