Heat a large saucepan over a medium heat.
Add the butter or oil and add in the onion, leek, carrot, potato, mushroom and smoked salmon. Sauté for 2–3 minutes until softened.
Pour the wine into the pan and the cream and sage.
Bring to the boil and simmer for a minute or so until the potatoes are just softened.
Then add the fish pieces, bring back to a simmer. Cover with a lid and simmer gently for a further 2–3 minutes depending on the size of the fish pieces or until the fish are cooked through. Remove from the heat. Check the seasoning.
To serve, ladle the chowder into warmed serving bowls, piling plenty of the fish into the centre of each bowl.