Fermented Red Bean Curd (Nam Yu)

Nam yu is bean curd that has been fermented with red yeast rice, salt and rice wine until it breaks down into a soft, crumbly, deep-crimson paste. It is sold in glass jars, usually sitting in its own brine, and a single cube carries an enormous amount of flavour – salty, funky, faintly sweet and unmistakably winey.

It is the backbone of Cantonese and Vietnamese roast pork marinades, where it gives crispy pork belly and char siu their savoury depth and part of their reddish colour. It also turns up in braised dishes, in dipping sauces for hotpot, and stirred through stir-fried greens such as water spinach.

Do not confuse it with white fermented bean curd (fu yu), which is milder and saltier, or with red bean paste, which is a sweet dessert filling made from adzuki beans. Once opened, keep the jar in the fridge and it will last for months. A little goes a long way – start with one cube mashed into a marinade and adjust from there.

Nutritionally it is very high in sodium, so it is used as a seasoning rather than an ingredient in its own right. A single cube contributes roughly 200 to 300 milligrams of sodium along with a small amount of plant protein.