Majora's Mask is definitely a strong contender for being the hardest of all The Legend of Zelda games; its three-day timer ...
Goat Butter in Zelda: Tears of the Kingdom is an item that can be consumed or used in cooking meals to boost health, stamina, or add temporary status effects.
Goat Butter can be purchased from High Spirits ... The book states that it's an historical recipe that's dear to Zelda's family, making it both sentimental and beneficial to Link's cause.