This dish will keep in the refrigerator for up to 3 days or in the freezer for up to 1 month. The best way to reheat it is in a casserole, in a 375° oven for 30 to 40 minutes.
In a large saucepan, combine the corn, beans and pimento. Add the chili sauce and mustard and stir until thoroughly mixed. Stir in the tomatoes and their juice. Cover and bring to a boil over moderate heat. Lower the heat and simmer for 15 minutes to mellow the flavors. Garnish individual portions with the parsley if desired.