Whisk together all of the Greek Marinade ingredients in a large freezer bag and add chicken. Marinate 4 to 8 hours.
Remove chicken from fridge and let sit at room temperature 20 to 30 minutes.
Heat one tablespoon olive oil in a large non-stick skillet over medium high heat. Once very hot, drain chicken from marinade, pat dry and add to skillet.
Cook undisturbed for 3 to 4 minutes, or until nicely browned on one side. Turn chicken over, cover, and reduce heat to medium. Cook for approximately 4 to 6 more minutes (depending on thickness of chicken), or until chicken is cooked through. Remove to cutting board and let rest 5 minutes before slicing.
Meanwhile, grease and preheat the grill to medium heat, 375 to 450 degrees Fahrenheit.
Grill chicken undisturbed for 5 to 7 minutes per side, or until chicken is cooked through. (An inserted thermometer should read 165 degrees Fahrenheit.) Remove chicken from grill and let rest 5 minutes before slicing.