Rinse and scrub the clams in cold water. Pick out and discard any clams with opened shells.
In a saucepan or wok with lid, heat 1 tbsp cooking oil over medium heat. Add 3 cloves garlic, mincedand 1 tbsp ginger, minced to fry until fragrant, about 1 minute.
Add 1 tbsp miso and 1/4 cup rice wine, stirring until the miso is mostly dissolved. Add 1 lb clams and 1/4 cup water. Cover and cook for 3-5 minutes, until clams begin to open.
Transfer opened clams to the serving dish, leaving the sauce in the pan. Discard any clams that don't open. Reduce heat to low and add 2 tbsp butter, stirring constantly until fully melted into the sauce.
Spoon the sauce over the clams and garnish with cilantro. Serve with steamed rice, crusty bread, or over pasta.
