The final stop, in Ho Chi Minh City (formerly Saigon), includes chef-led cooking classes and a street-food tour -- and boundless opportunities for trying snacks such as banh mi (sandwiches), pho (spicy noodle soup), goi du du (green papaya salad) and banh xeo (rice pancakes with pork and shrimp).

CNN: Exotic culinary tours around the world

At the centre of its bewilderingly long menu is pho, traditional Vietnamese noodle soup served with a choice of beef, where the integral ingredient is a broth simmered slowly for many hours to develop its rich, deep flavour.

BBC: Cheap ethnic eats in London