Bún bò Huế uses round rice vermicelli (bún) in a spicy, lemongrass-heavy broth built from beef and pork bones, seasoned with mắm ruốc (fermented shrimp paste) and chilli oil, topped with sliced beef shank, pork knuckle, and cha lua (Vietnamese pork sausage).
The distinguishing elements
- Broth: lemongrass-forward and spicier than pho; the shrimp paste adds fermented depth
- Noodles: round thick vermicelli (bún), not the flat banh pho of pho
- Protein: multiple cuts including the gelatinous pork knuckle
- Chilli oil: added directly to the bowl; the heat level is higher than most Vietnamese soups
Mắm ruốc (fermented shrimp paste)
This is the ingredient that separates Huế cuisine from Hanoi cuisine. The paste is intensely funky and salty — it is used in small quantities (a tablespoon per litre of broth) as a seasoning, not a dominant flavour.