Combine the ranch dressing mix with the olive oil, the red wine vinegar, the Mrs. Dash and the garlic powder into a small mixing bowl.
Place the chicken breasts into the mixture and marinate (covered) in the refrigerator overnight if possible (but not necessary).
Pre-heat a skillet with a drop of olive oil on a medium flame. Place marinated chicken in the skillet and cook on one side for 4 minutes, uncovered. Turn over chicken and continue cooking until the chicken is fully cooked and no longer pink inside