This chowder is enriched with a cream reduction.
In a small saucepan, simmer, whisking occasionally,  until reduced to 2/3 cup:
      1 cup heavy cream
Meanwhile, melt in a soup pot over medium heat:
      1 tablespoon unsalted butter
Add and cook, stirring, until the leeks are tender but not browned, 5 to 10 minutes:
      2 medium leeks (white part only), cleaned thoroughly and chopped
      1/4 cup dry vermouth
      1 clove garlic, minced
Stir in:
      3 cups Fish Stock, Fish Fumet, or Express Fish Broth
      2 red or white new potatoes, diced
      1/2 teaspoon salt
Bring to a boil, reduce the heat, and simmer until the potatoes are cooked, 10 to 15 minutes. Reduce the heat to low. Add the reduced cream along with:
      12 ounces salmon fillet
      1/4 teaspoon ground black pepper or ground white pepper
Simmer just until the salmon is cooked, 8 to 10 minutes, depending on the thickness of the fish. Gently break apart the fillet with a wooden spoon. Serve immediately, garnished with:
      Small dill sprigs