1. In a medium bowl, whisk together the olive oil, red wine vinegar, soy sauce, lemon juice, Worcestershire sauce, and Dijon mustard until well combined. Add the minced garlic, parsley, basil, oregano, and black pepper. Whisk everything together until the marinade blends fully and emulsifies slightly.

2. If using chicken breasts, pound them to an even thickness (about 3/4 inch) using a meat mallet or rolling pin. Pat the chicken dry with paper towels before marinating.

3. Place chicken in a large ziplock bag or shallow dish. Pour the marinade over the chicken, making sure every piece gets well coated. Seal the bag or cover the dish and refrigerate for at least 2 hours, or up to 8 hours for maximum flavor. Flip the bag halfway through for even coverage.

4. Preheat your grill to medium-high heat and oil the grates well. Remove chicken from the marinade, letting excess drip off (discard the used marinade). Grill for 5 to 7 minutes per side, or until the internal temperature reaches 165°F and the chicken shows beautiful grill marks.

5. Transfer the grilled chicken to a cutting board and tent loosely with foil. Let it rest for 5 minutes before slicing.