If you're into the mountain biome, then I think the best stamina food would be eyescream.
3 greydwarf eyes and 1 freeze glad each. That will give you 65 stamina over the 60 stamina of onion soup. It also lasts for 25 minutes instead of the 20 minutes from onion soup.

Either way, they all only stack to 10. Even in the endgame, the best foods only stack to 10. Though, some do last for 30 minutes. If you're using 3 foods that last for 30 minutes and you have a stack of 10, that's 5 hours of gameplay before you need to restock.