Mix beans with corn. Heat vinegar, sugar, onions, salt, mustard seed and pepper to boiling. Cover and cook five minutes.
Combine water and cornstarch. Add gradually to vinegar mixture and bring to boil, stirring constantly. Boil one minute and remove from heat. Pour over bean mixture and stir well.
Refrigerate at least four hours, stirring occasionally. NOTES: This is a nice alternative to three bean salad.Servings: