"One bowl of tripe stew for me."
Translation:I hoʻokahi pola ʻōpū kū naʻu.
This is a good question. "ʻŌpū kū" and "pipi kū" are a couple of the uncommon exceptions to the general rule of descriptive words coming after "nouns" in Hawaiian. I can't say for sure why this is, but it may have something to do with their origin in the English "tripe stew" and "beef stew".
Good question! Hoʻokahi is used for talking about an amount of people or things, when that amount is one (one bowl of tripe stew, one sulky child on the playground, one hat left). ʻEkahi on the other hand is used for the number one, when counting (ʻekahi, ʻelua, ʻekolu, etc.) or in reciting a number, such as a phone number (315-2671 -> ʻekolu, ʻekahi, ʻelima - ʻelua, ʻeono, ʻehiku, ʻekahi).