1 tablespoon butter 2
tablespoons flour 2 cups
fish stock to taste salt and ground white
pepper
Melt the
butter in a heavy bottom medium saucepan. stir in the flour to make a roux, and
cook over low heat until slightly brown. Pour in the fish stock, whipping until
smooth. Bring to a boil, stirring occasionally until the sauce thickens. Simmer
for 5 minutes and season to taste.