Add the flour one-fourth cup at a time. Beat with a wooden spoon until the mixture begins to thicken and pull away from the sides of the pan. Continue to cook, stirring, for 5 minutes. Beat in the egg yolks, one at a time, with a wooden spoon. Whip the egg whites at high speed until they form stiff peaks. When ready to serve, add the cooled base to the meringue.