Scald 2 1/4 cups of the milk.
Mix cornstarch, sugar, and salt in a bowl, then add remaining milk, a little at a time.
When smooth, combine with scalded milk and cook over a moderate heat, stirring constantly, until thick and bubbly.
Remove from heat and gradually beat a small amount into the egg.
Blend with remaining mixture, add rose water or vanilla, and cook over a low heat for 2 minutes, stirring constantly.
Pour into a 1 quart mold and chill until firm.
Unmold on serving platter and surround with sweetened berries.