1/4 c. dry mustard
1 1/2 tbsp. cornstarch
1/2 tsp. salt
1/4 c. sugar
2/3 c. water
1/3 c. vinegar

Mix mustard with a little water. Let stand. Mix cornstarch, sugar, salt with remainder of water until smooth. Add vinegar. Cook over low heat, stirring constantly for 5 minutes. Remove from heat. Cool. Add mustard. Mix well. Yield 1 cup.