Its name means 'brains' in Malay, a nod purely to the paste's soft, whitish-grey texture before grilling, not to any actual ingredient.
Ground mackerel is mixed with chilli, turmeric, lemongrass, and coconut milk into a spiced paste, wrapped in nipah palm leaves gathered along the Muar River, and grilled over charcoal until the parcel chars and the fish inside turns smoky and firm. Muar's market stalls sell it warm, straight off the grill, still in its leaf wrapper.