3/4 c. white sugar
3 tbsp. cornstarch
1/4 tsp. salt
3/4 c. cold water
2 tbsp. grated lemon rind
1 tbsp. butter
1/3 c. lemon juice

Mix sugar, cornstarch and salt in a saucepan. Gradually stir in water. Bring to a rolling boil; boil one minute, stirring constantly. Remove from heat. Add lemon rind and butter. Gradually stir in lemon juice. Cool thoroughly before using.