Thai salted pickled mustard, also known as "Phak Dong" in Thai, is a popular condiment and ingredient in Thai cuisine. It is made from young mustard greens that are fermented with salt and sometimes other seasonings. 

The process of making salted pickled mustard involves washing the mustard greens and then layering them with salt in a container. The greens are left to ferment for a period of time, typically several weeks, allowing the flavours to develop and the vegetables to soften.

The resulting pickled mustard has a distinctive tangy, salty, and slightly sour taste. It is often enjoyed as a condiment or side dish, adding a refreshing and piquant element to meals. It can be eaten on its own or served alongside rice dishes, stir-fries, soups, or curries.

In Thai cuisine, salted pickled mustard is commonly used in dishes like stir-fried salted pickled mustard with pork, salted pickled mustard soup, or in various Thai salads. Its unique flavour and texture make it a versatile ingredient that adds complexity and depth to a wide range of dishes.