Put the oil and chopped garlic in a frying pan, and saute over low heat. When the oil is fragrant, add the scrubbed and de-sanded clams, and saute over high heat.
Add the sake, cover with a lid and let them steam (about 2 minutes). When the clams open up, add the soy sauce and chopped green onions, mix it all up and it's done.
How to de-sand the clams...Put the clams in salted water (1 teaspoon of salt to every 200 ml of water) and leave in a dark place covered with newspaper, until they've spit out the sand inside them.
For clams you've dug yourself, allow 3 to 4 hours; for clams you bought at the supermarket, allow about an hour. Wash the clams under running water, rubbing the shells together. Drain in a colander.
Story Behind this Recipe
This is my mother's recipe. We can dig clams nearby, so whenever we went clam digging when I was a child, I used to ask her to make these sake-steamed clams for us.
Some clams are very salty, so taste before adding the soy sauce. It's best to de-sand the clams in a wide, shallow container so that the clams are in a single layer. If you don't have a container like that though, a bowl is fine.