The soup's jet-black color comes from kluwek, a fermented nut that's actually poisonous when raw and has to be properly fermented before it's safe to cook with — and popular tradition traces a version of the dish to a 901 CE Javanese inscription, though scholars still debate whether the term actually appears in the original text.
Beef is slow-simmered in a dark, deeply savory broth colored and flavored by fermented kluwek nuts, along with lemongrass, galangal, and candlenut, then served over rice with bean sprouts, salted egg, and a spoon of chili paste. East Java's street warungs keep the broth simmering in huge pots all day.
Sate (Skewered Grilled Meat)
Gado-Gado (Vegetable Salad with Peanut Sauce)