The noodles are red-brown, not white: bánh đa đỏ, Hai Phong's own flat rice noodle, is what sets this soup apart.
Flat red rice noodles in a broth built on pounded field crabs (cua đồng), topped with the soft crab 'curds', pork and greens, served hot at breakfast stalls with shrimp paste and chili on the side.