"Bun" simply refers to the rice vermicelli noodles, and "ca" is fish, but this breakfast noodle soup is so much more than the sum of its parts. Plenty of bun ca (not to be confused with bun cha) variations abound, but in northern Vietnam, dill is a popular ingredient and is used liberally here, more as a vegetable than an herb. The fish-pork broth is tinged red with tomatoes, which are included for color rather than taste. If bun isn't to your liking, you can also get banh da, dried flat noodles flavored with tea powder, instead.