Cooked Salad Dressing - cooking recipe

Ingredients

3 Tbsp. sugar (level)
1 1/2 Tbsp. flour
1 tsp. salt
1 tsp. dry mustard
1 egg
3/4 c. milk
4 Tbsp. vinegar
1 Tbsp. butter

Preparation

Mix in order given:
sugar, flour, salt and mustard.
Then add egg and milk.
Then add vinegar (add this slowly).
Cook over hot water, stirring constantly, until thick.
Add butter.
Blend thoroughly; cool.