Melt the butter and sieve in the flour. When the flour is golden yellow, deglaze with the milk. Stir well and add the white wine. Let everything simmer over medium heat for 10 minutes. Stir more often, add the Cafe de Paris and the dill. Cut the spring onions into thin rings and add. Cut the salmon into strips and add. Let it steep for 5 minutes on a low heat. Season to taste with the spices and serve immediately. If the sauce gets too thick, add a little water. Super green tagliatelle go well with it.