Elephant ear ornamentals are eaten in other places so much they are considered the 14th most popular vegetable in the world Cool Colocasias - Elephant Ears for the Garden | Article by Plant Delights Nursery
There are also 110 edible bamboo plants https://www.guaduabamboo.com/types/edible-bamboo-species but like poke greens make sure you cook bamboo! With bamboo you need to make sure it’s the right type to eat! I would love to have a cold hardy edible bamboo someday.