Heat the fish stock together with the wine and reduce to a high heat for about 10 minutes. Add the cream and reduce a little more until the sauce is slightly creamy (possibly a little sauce thickener), season with salt.
Clean the spring onions and cut into rings. Clean and dice the salmon.
Add onion rings and diced salmon to the sauce and let it steep for a few minutes.
Best to serve directly on the plate and sprinkle with black pepper from the mill at the table!