Ontjom, or more recently referred to as onchom, is a product closely related to tempeh. Onchom is more commonly produced in West Java, Indonesia. Unlike tempeh, onchom is mainly prepared from ground nut [Arahis hypogea], but other products, including okara [soy fiber left over from manufacturing soy milk ] or coconut press-cake may also be used. A mold which produces orange-red spores, Neurospora sitophila is used to ferment onchom. In contrast to tempeh, sporulation of the orange-red mold is encouraged in onchom; whereas sporulation is avoided in culturing tempeh.
A carpet of almost a brilliant orange-red mold should cover the top layer of traditional onchom, then it is ready for consumption. Deep fat fried onchom with coconut oil, has a delicate mushroom-like flavour, with overtones of a sweet-nutty flavour and aroma.