Put the turbot steaks in a pan with the onions
and enough wine and stock to cover. Bring to a boil, then reduce the heat and poach
gently for 15 minutes. Remove the fish
to a serving dish and keep warm. Strain
the liquid and reserve.
the pickled walnuts
. Combine them with the butter
, 1 cup wine/stock mixture and the chopped watercress
. Season. Bring to a boil and simmer
for a few minutes. Pour this sauce
over the fish, garnish
with pickled walnut halves and serve.