Bring the water to a rolling boil. Add the pork cartilage, then reduce to a gentle simmer and cook for about 1 hour, until tender.
500 g pork cartilage pieces, 3 liters water
Meanwhile, dry-toast the galangal, lemongrass, shallots, makrut lime leaves, and cilantro roots in a pan over low heat until aromatic, then pound into a fine paste.