Step 1

Bring all the broth ingredients to a boil in a large pot. Drop the heat below a simmer and let this cook gently for 30 to 45 minutes. Strain and keep warm. Pick off salmon meat and reserve.

Step 2

In a soup pot, heat the butter over medium-high heat and cook the sliced onion until wilted and transparent, but not browned.

Step 3

Pour in the broth and potatoes, bring to a simmer and add salt to taste. Simmer gently until the potatoes are tender.

Step 4

Add the salmon, either picked from the bones or freshly diced, plus the herbs and heavy cream. Let this simmer 5 minutes.

Step 5

With a ladle in one hand and a whisk or fork in the other, slowly ladle some hot broth into the egg yolks, all the while whisking the egg yolks. You want to temper them so the yolks won't curdle in the soup. Whisk in another ladle, then one more. Pour this into the soup, stir well and turn the heat as low as it will go. Let this warm up a minute or three, then serve at once.