Rawon is a Javanese black beef soup that has its origins in Surabaya, one of the provinces in East Java, Indonesia. This aromatic, richly flavored soup is one of the traditional dishes of Indonesia and is typically served over rice or glass noodles. The main spice in this dish is keluak, a black nut that is the seed of the fruit of the Kepayang tree found in the region. This spice is responsible for giving the soup its exotic, deep-black color.
This soup or stew is considered to be one of the distinctive foods of Jawa Timur and eastern Jawa Tengah. It comes with a variety of accompaniments, such as shrimp crackers, mung bean sprouts, salted duck eggs, and sambal chili sauce. Sometimes, it is referred to as Nasi Rowan or Rawon rice in Indonesia when served over a bowl of rice.
A bonanza of various flavors, this black soup is typically served with a large assortment of colorful garnishes. Some of the more common garnishes are green onion, blanched bean sprouts, and crispy shallot flakes. It may also be garnished with wedges of boiled egg and Chinese celery sticks. While it is served as a main course in both East and Central Java, there are subtle differences in both its appearance and taste in the two regions. The Rawon made in Central Java is sweeter and blacker in color than the Rawon stew found in Eastern Java.
The beef in this soup is diced into small bite sizes, and it is sometimes pressure cooked until it gets soft. The stew contains a potent ground-up spice mix made of an array of fresh and dry ingredients — red chillies, garlic, shallot, and candlenut — which thickens the dish. It also has turmeric, galangale, which is a type of ginger, and keluak. These spices are usually ground up, sauteed in oil, and added to boiling beef stock that contains the diced beef. Sometimes, it is also seasoned with kaffir lime leaves, leek, bay leaves, and lemongrass.
The unique, nutty flavor of the Rawon soup comes from the black keluak nut. It is a hard-shelled seed that resembles a Brazil nut and is considered to be difficult to find. This is because the seeds are harvested from wild Kepayang trees that require years to mature; they aren't cultivated commercially because it isn't economically viable. The fruit and seeds are poisonous, and they require rigorous processing before they can be used as food. Keluak can sometimes be found in premixed spice pastes.