Dice the potatoes, leek, and carrots.
Heat the butter in a decent-sized saucepan and sauté the leek and carrot. Season and leave to take on colour, stirring occasionally.
Dust with flour, add the potatoes and cover with stock. Cook for around 20 minutes until the potatoes soften.
Mix in the cream, dill, sugar, and vinegar.
Remove and discard the skin from the salmon and cut into decent-sized chunks. Place these into the gently-bubbling saucepan and leave to cook through for around five minutes.