Melt 2 tbsp butter in a pan on medium-high heat and add the leeks and carrots. Saute until starting to become golden and crispy. Dump them into a large pot and pour in the fish stock.
Melt the remaining 2 tbsp butter in the original pan and saute the potatoes until starting to become golden before adding them to the fish stock as well. Add a pinch of allspice and salt/pepper, to taste.
Bring the pot to a simmer and let cook for about 10-15 minutes.
At this point, add the salmon,cream, and half of the dill and let simmer for an additional 6 minutes.
Serve warm, garnished with the remaining dill.
Notes
See above for tips on removing the salmon skin and how to properly prepare leeks!