Fukagawa-meshi

Method

1. Purge the clams first: spread 250 g of live asari in a single layer in a shallow bowl and cover with a 3% brine made by dissolving 15 g of salt in 500 ml of cold water, so the shells are just submerged. Cover with a sheet of paper to darken the bowl and leave in a cool place for 1 hour, until the clams have spat out their sand. Discard any that stay open when tapped, then scrub the shells against each other under cold running water.
2. Wash 90 g of short-grain rice in several changes of cold water, swirling with your fingertips until the water runs only faintly cloudy. Drain in a sieve for 15 minutes, then put it in a small heavy pan with 110 ml of water. Bring to the boil uncovered, clamp on the lid, cook on the lowest heat for 12 minutes, then take off the heat and let it steam, still covered, for 10 minutes. Fluff with a wet paddle.
3. While the rice steams, put the drained clams into a wide pan with 1 tbsp of sake and 100 ml of water. Cover and set over medium-high heat for 3-4 minutes, shaking the pan once, until the shells gape open. Pull the pan off the heat the moment most are open — overcooked clams turn rubbery — and discard any that stayed shut.