Aunt Annie'S Mustard
["1 egg, beaten", "2 rounded Tbsp. dry mustard", "1 tsp. salt", "1 tsp. sugar", "5 Tbsp. vinegar"]
["Mix all ingredients in double boiler and cook, stirring constantly until thick.", "Store in refrigerator. Keeps indefinitely."]
["egg", "mustard", "salt", "sugar", "vinegar"]