Fun Territory Defense by the Optimistic Lord

A man was reincarnated as Van, a boy of noble birth, who grew up to become a child prodigy through hard work. But when it was discovered that he possessed "production magic," he was immediately relegated to a remote village. However, his magic, which was called useless, turned out to be truly extraordinary, capable of producing anything as long as he had the right ingredients! With the knowledge from his previous life and the overpowered magic, the small, poor village will grow to become into a great city.