boil with the salt and butter. a soon as the butter melts remove the pan from heat and add all the flour at once a beat with a wooden spoon. then beat over medium high heat several minutes until it forms a mass. remove from the heat and one at a time beat in the eggs, then the egg whites.
set the saucepan over a bowl of ice water to cool down. leave it there while you prepare the fish. make sure it well chilled before combining the two.
cook the butter and flour together slowly about 2 minutes, not letting it turn color. remove from heat and beat in the boiling 