In a medium saucepan whisk together eggs, whites, sugar and salt. Gradually stir in low-fat milk. Cook over low heat, stirring, until mixture thickens and coats back of spoon, about 25 minutes (should register 170 degrees to 175 degrees on instant-read thermometer); do not let boil. Pour into bowl. Stir in vanilla and 1/2 teaspoon nutmeg. Refrigerate about 3 hours or until cold.
Pour evaporated milk into ice-cube tray. Freeze 2 hours or until almost frozen. Empty into a large metal bowl. Beat at medium speed until soft peaks form. Gently fold into chilled egg mixture.
To serve, pour into chilled glasses and garnish with additional nutmeg, if desired.