In a medium bowl, stir together the olive oil, bottled ranch dressing, Worcestershire sauce, Greek seasoning, lemon juice, and white vinegar. This creates a rich and tangy marinade that will infuse the chicken with flavor.
Pound the chicken breast to a thickness of about 1/4 inch. This step is essential as it helps the chicken cook evenly and stay juicy. You can use a meat mallet or a heavy skillet for this task.
Once pounded, place the chicken in a gallon-sized ziplock bag. Pour the marinade over the chicken and seal the bag, ensuring the chicken is well-coated. Refrigerate for at least 8 hours or overnight for maximum flavor.
Preheat your grill to medium-high heat. This is crucial for achieving that perfect char while keeping the chicken tender.
Remove the chicken from the marinade, letting any excess drip off. Place the marinated chicken on the grill, ensuring not to overcrowd the grill.
Grill the chicken for 8 to 12 minutes, flipping halfway through. The chicken is done when it's no longer pink in the center, and the juices run clear. Use a meat thermometer to ensure an internal temperature of 165°F.
Once cooked, remove the chicken from the grill and let it rest for a few minutes. This allows the juices to redistribute, ensuring each bite is moist and flavorful.
Slice the chicken and serve it with your favorite sides. Enjoy the delicious flavors of your Grilled Greek Ranch Chicken!