We review the salmon loins well to make sure they have no remains of scales or bones. We peel the onion and cut it into thin julienne strips. Heat a little oil in a frying pan and fry it over very low heat.
When it is tender we add the flour and stir to integrate. Next we add the white wine and, over high heat, we let it slightly evaporate. Add the liquid cream and season to taste.
We introduce the salmon in the sauce when it begins to boil and season again. We cover the pan and we let the loins cook for about five minutes. Serve immediately by sprinkling each serving with a little chopped fresh parsley or chives.