Where to farm elixir?

Edit2: I've done it! I'm dumb. Buffs, debuffs and NO ELIXIERS USED Hehehe

Hi there! I just got the captain back into my party, but the bossfight was a nightmare. I have spent all my 11 elixiers in that fight and barely made it.

Please... Where are elixiers to farm, without the funi-thing? I think I have to load the save before the fight or else I am screwed.

(Sorry for my bad english)

Edit: "Funi" was the name I was missing