Bánh canh is the Vietnamese noodle soup known for thick, chewy noodles made from rice flour and tapioca starch.
The noodles are round and substantially thicker than the strands used in phở or bún. Combining rice flour with tapioca starch gives them a soft but elastic texture. They may be cut by hand or extruded, and their appearance can resemble Japanese udon, although the ingredients and Vietnamese preparations differ.
Bánh canh is a broad family of regional soups rather than one single recipe. Popular versions include bánh canh cua with crab, bánh canh ghẹ with swimming crab, bánh canh chả cá with fish cake, and bánh canh giò heo with pork hock. Broths may be based on seafood, pork bones or both.
The word bánh in this context refers to a flour-based preparation, while canh means soup. It should not be confused with bún, whose thinner rice vermicelli is used in many other Vietnamese noodle dishes.