In a large soup pot over medium-high heat, melt 2 tablespoons of unsalted butter until bubbling. Add the sliced carrots and leeks, seasoning them with a pinch of kosher salt. Sauté for about 8-10 minutes, stirring occasionally, until the vegetables are softened and fragrant.

Carefully stir in 3 cups of seafood stock and the cubed Yukon Gold potatoes. Increase the heat to bring the mixture to a rolling boil, then reduce to a gentle simmer. Allow the soup to cook uncovered for 10-15 minutes, or until the potatoes are tender.

Next, gently fold in the 1-inch salmon cubes along with ¾ cup of crème fraîche. Stir to combine without breaking the fish pieces. Cover the pot and continue simmering for 3-5 minutes.

Once the salmon is cooked, stir in about 1 cup of freshly chopped dill. Taste the soup and adjust seasoning by adding more kosher salt and freshly ground black pepper as needed.

Ladle the creamy Finnish salmon soup into warm bowls, garnishing each serving with extra dill and a sprinkle of freshly cracked black pepper. Serve with crusty bread or a light salad.