Found a old box of recipe cards (70/80's era) and this one seems to be good and easy. Times are estimated.
- Melt butter in a saucepan over medium heat and then add flour and stir for a minute or two until combined.
- Remove pan from the heat and add milk and cream and stir until combines and then return to the heat.
- Stir with a wooden spoon until the sauce boils.
- Reduce the heat and simmer for 2 minutes.
- Remove from the heat and stir in the wine and season with the salt and pepper and then add the mustard and mix well.
- Sprinkle the gelatine over the water and when dissolved or softened add to the sauce and stir.
- Return the pan to the heat and stir for 4 minutes but DO NOT BOIL.
- Put the sauce in a mixer bowl and add the salmon and mix on medium speed until smooth.
- Put into serving bowl and cover and refrigerate overnight.