Lemon Sauce - cooking recipe

Ingredients

1/2 c. sugar
1 Tbsp. cornstarch
1/8 tsp. salt
1 c. boiling water
1 egg yolk
2 Tbsp. butter
2 Tbsp. lemon juice

Preparation

Mix sugar, cornstarch and salt.
Add boiling water slowly, stirring constantly.
Boil for 5 minutes.
Remove from fire; pour over beaten egg yolk and add butter and lemon juice.