Bún Riêu

Bún riêu is rice noodles in a tomato-red broth built around a loose, curd-like crab-paste cake that breaks apart as it cooks. Ground freshwater crab, mixed with egg, sets into soft, crumbly clumps that float through the broth rather than staying in one piece — that loose, curdled texture is the dish's signature and the detail a bowl of bún riêu is judged on.

What it really is

Freshwater crab, shell and all, gets ground fine and strained, then the crab liquid simmers with egg and often a little pork until it sets into loose, curd-like clumps that rise to the top of the pot — this crab cake, riêu, gives the dish its name. Tomato cooks down into the broth until it turns a deep red-orange, and the finished soup goes over rice vermicelli with fried tofu, a few water spinach stems and a heavy scatter of fresh herbs, finished with a spoonful of fermented shrimp paste stirred in at the table for those who want the extra depth.

The crab cake is meant to look loosely curdled, not smooth or compact. A tightly set, uniform crab cake reads as a mistake in the kitchen — the soft, broken texture is what happens naturally when crab liquid and egg set together, and cooks don't try to smooth it out.

How it's served

• Hot, in a bowl, broth ladled over rice noodles with the crab cake broken into pieces.
• With fried tofu, water spinach and a heavy scatter of fresh herbs.
• With a spoonful of fermented shrimp paste offered separately, stirred in at the diner's discretion.

How to write it on the menu

• Flag the shellfish from the crab and the fish sauce and shrimp paste used in seasoning.
• Say if a vegetarian crab-free version, built on tofu and mushroom, is available, since the crab is otherwise central to the dish.
• Note the shrimp paste is optional and served separately, since its fermented flavour is assertive and not every guest will want it.