Japanese art of simmering ingredients in seasoned dashi-based liquid — fundamentally different from Western braising. Uses shorter, gentler cooking to infuse flavour while preserving each ingredient's identity. The drop lid (otoshi-buta) sits directly on the food surface, keeping ingredients submerged in minimal liquid.
Drop lid circulates simmering liquid over food as it bubbles underneath, keeps lightweight ingredients submerged without much liquid, prevents vigorous boiling. Less liquid means more concentrated seasoning. Seasoning order matters: sake first (alcohol cooks off, tenderises), then mirin (sweetness), then soy sauce last (added early it toughens protein surfaces). Sugar before salt — larger molecules penetrate first. Cooking times are 15–30 minutes, much shorter than Western braising.
Parchment paper circle with a few holes works as a drop lid. For fish nimono (nitsuke): 8–12 minutes for most fillets. For root vegetables: par-boil in plain water first to remove bitterness, then transfer to seasoned liquid. Leftover simmering liquid (tare) reduces into a glaze.
Too much liquid — nimono isn't soup. Boiling too vigorously. Adding soy sauce too early. Not using a drop lid. Cooking too long — ingredients should retain shape and identity.