Sauté shallots (chopped) in white wine and vinegar until they become puree. Slowly add small pieces of chilled butter form and stir until the whole becomes a rich creamy sauce. Season to taste with salt, pepper and lemon .
The best accompaniment to poached salmon fillet.
Very important: the Sancerre must be good: Who takes a supermarket Sancerre should not be surprised if the sauce does not taste good. And the rest can be enjoyed exquisitely with the meal I poach the salmon in a mixture 50/50 fish stock and wine.
*Wine recommendation
The typicitè of a Sancerre may suffer from this, but it is a wonderfully concentrated, delightful wine.