Aunt Judy's Texas Cream Pie

Rebecca McElroy, from her Aunt Judy, a true Stratford lady.
Makes 2 pies
Ingredients:

1/2 c. sugar
1 heaping T. all purpose flour
2 c. milk
1 pkg. plain gelatin
1/4 c. warm water
4 eggs, separated
2 tsp. vanilla
1/4 tsp. cream of tartar
dash of salt
1/2 c. sugar
Directions:

Combine flour , milk, and the 1/2 c of sugar. Cook for a few minutes, then add the gelatin that has been dissolved the the warm water. Continue cooking until it starts to thicken. Add the beaten egg yolks and cook three more minutes. Add the vanilla and cool the mixture. Beat the egg whites with the cream of tartar, salt, and the 1/2 cup of sugar. Fold into cooled cream mixture. Pour into cool pie crust and refrigerate. Cover with whipped cream and sprinkle with grated semi-sweet chocolate.