1. Place the tomato soup, olive oil, vegetable oil, cider vinegar, sugar, onion, Worcestershire sauce, garlic, and dry mustard in a blender or food processor fitted with a steel blade and blend until smooth, about 45 sec. You will have more marinade then you will need for 12 chicken breast halves.

NOTE: Any marinade you don't use can be stored in a glass jar in the refrigerator for up to two weeks. Heat the extra marinade and serve it as a sauce for the chicken. Or, you can use the marinade as a vinaigrette for salad.