Wikipedia
Guoba (鍋耙, 鍋巴, 锅巴, lit. "pan adherents"), sometimes known as mi guoba (米鍋耙, lit. rice guoba) is a Chinese food ingredient consisting of scorched rice. Traditionally guoba forms during the boiling of rice over direct heat from a flame. This results in the formation of a crust of scorched rice on the bottom of the wok or cooking vessel. This scorched rice has a firm and crunchy texture with a slight toasted flavour, and is sometimes eaten as a snack.
Guoba is also used as an ingredient in many Chinese dishes with thick sauces, since the bland taste of the scorched rice takes on the flavour of the sauces. Guoba is also served in soups and stews and prominently featured in Szechuan cuisine. Since demand for guoba outstrips traditional production and modern ways of cooking rice (in electric rice cookers) do not produce it, guoba has been commercially manufactured since the late 20th century.
In Vietnamese cuisine, a similar food is called cơm cháy (literally "scorched rice"). It is typically fried in oil until golden brown, then topped with chà bông ( pork floss) or tôm khô ( dried shrimp), mỡ hành (chopped scallions cooked by pouring boiling oil over them to release their aroma), and chili paste to produce a popular dish called cơm cháy chà bông or cơm cháy tôm khô (although both the pork and shrimp may be used, in which case the dish is called cơm cháy chà bông tôm khô or cơm cháy tôm khô chà bông). Cơm cháy may be made from the crust of rice left over from cooking rice in an iron pot, or, more commonly since the advent of electric rice cookers in the late 20th century, from leftover rice that is fried in oil over high heat to acquire a crispy texture.
In Iranian cuisine, the crispy rice that forms at the bottom of the pot during slow cooking is considered a delicacy. It is called Tahdig in Persian. Sometimes, thin slices of vegetables are added at the bottom of the pot to combine with the Tahdig. It is considered the best part of the rice. Long grain Iranian rice is used, which is similar to Basmati in taste and texture.