Place the clams in a large bowl and cover them with the water. Add the salt and give everything a swish. Let sit for 1 hour.
907g (2lbs) littleneck or manilla clams, 4 cups cold water, ¼ cup salt
While the clams are soaking, place the butter in a large heavy bottom pot. Melt the butter over medium heat. Add the onion and a pinch of salt once the butter is foamy. Sauté over medium-low until the onion is translucent.
3 tbsp unsalted butter, 1 yellow onion
Add the celery and carrots to the pot and sauté until softened. Deglaze the pot with the dry vermouth and stir in the potatoes. Toss to coat.
3 carrots, 3 stalks celery, ½ cup dry vermouth **, 350g (12oz) baby red potatoes
Pour in the stock and clam juice and bring the mixture up to a boil. Reduce to a simmer and add the bay leaves. Simmer for 20-30 minutes or until the potatoes are very tender.
3 cups seafood stock ***, 1 (236 ml, 8 fl oz) bottle clam juice, 2 bay leaves
While the soup is simmering, check on the clams. Drain the clams and remove any that appear open. Rap each open clam on the counter, this should prompt the clam to shut. If it doesn't, discard the clam. Set the clams aside.
When the potatoes are tender, add the miso to the pot. Stir until the paste dissolves. Add the evaporated milk and bring the chowder back up to a rapid simmer. Add the clams and cover. Let cook for 7-10 minutes or until all the clam shells have opened.
2 tbsp white miso, 2 (354ml, 12 fl oz) cans evaporated milk
Ladle the soup into bowls and garnish with the sesame oil, furikake, and celery leaves. Serve immediately.
sesame oil, furikake, celery leaves