To prepare a delicious 'bun oc', makers have to be careful to choose a good snail that is very fat and not soaked in the water too long. Then they choose the best bun (rice noodle). Spices for bun oc include many things, including tomato, vinegar, oil, pepper, salt, sugar and many kinds of aromatic vegetables together with salad and banana flowers in small slices.

Cooked snails are arranged neatly in a bowl of bun with fried tofu and fresh herbs, and the dish is finished with a hot, sweet and sour broth that is poured over all of the cold ingredients. Finally, a few slices of cooked tomatoes are placed on top.

One of the oldest places serving bun oc in Hanoi is in Hang Chai street. Sometimes when it is too busy, guests have to hold their bowls in their hands because there are not enough tables. Still, it is a fun experience if you want to eat like a local.