The name refers to the vessel rather than the food: kyay oh means 'copper pot', after the small metal pot the soup was traditionally cooked and served in.
Rice vermicelli is served in a light pork broth loaded with a mix of pork offal, meatballs and sometimes wontons, garnished with fried garlic and coriander. Yangon's Chinatown and its surrounding noodle shops are where the dish is most firmly rooted.