Pour the crÅme fraöche into a well chilled bowl. Add 2 tablespoons ice water. Whip the crÅme fraöche until it becomes mousse-like. Cut the Roquefort and butter into small pieces and process them in a food processor. Fold the crÅme fraöche and the chopped nuts into the Roquefort-butter mixture. Place in a terrine and decorate with walnuts. Eat with country bread.
