Clean and wash sorrel and, except for a little, cut it finely. Fish wash, dab dry, cut into about 12 pieces and salt
Boil the wine. Cover the fish and let it simmer at low heat for about 3 minutes. Remove and keep warm. Pour cream into the wine and let it boil down for about 1/3 at high heat for about 7 minutes
Dice butter. Gradually stir into the sauce with a whisk (do not boil any more!). Stir in sorrel. Season to taste with salt, pepper and lemon juice. Serve fish with sauce. Garnish with remaining sorrel and possibly lemon. Serve with new butter potatoes and a fresh green salad