Elixir Soup

From Zelda Wiki.org

Elixir Soup is a special soup made for Link by his Grandmother in The Wind Waker. It heals both his health and magic and also doubles his attack power until he takes damage. It is stored in bottles like a Potion and each bottle can hold two helpings.

Link can get the soup after he cures his grandma, when she falls ill. Link did this by going to Fairy Fountain on Outset Island to get a fairy to heal her. After healed, Link can always get a bottle of soup from here when he runs out.