1 tbsp. butter
1/2 c. vinegar
1/2 c. hot water
1 1/2 c. sugar
1 egg
1 tsp. flour
1 tsp. lemon extract

Mix vinegar and water. Add sugar and flour mixture. Add butter and beaten eggs. Set over hot water and cook until thicken. Remove from stove and add lemon extract. Pour mixture in unbaked shells and bake in moderate oven at 350 degrees about 30 minutes.