The Supreme Gourd is the best gourd in the game as you can use it 10 times to get health back and there are multiple steps to getting it. First you need to have upgraded your gourd so it can hold nine sips. At the monkey in the Uptown or in Chapter 1 by finding enough Luya fragrant finds. You can, by the way, also buy these at the monkey, then from the Rishza Palace shrine in Chapter 5. You cannot miss. Simply go like this, cross the bridge, head right and then eventually left inside this building, talk to the old man here, and then you can claim the Supreme Guard from the campfire nearby.