1 c. milk, heat to boil
1 egg, separated, use only yolks
1/2 c. milk
3 tbsp. corn starch
1/4 c. sugar
1/2 tsp. salt

Stir to paste - add to milk to thicken on medium heat. Then add beaten egg yolks - cook until thick. Take off heat to cool. Add 1 tablespoon butter and 1 teaspoon vanilla.