1.In a small bowl whisk together ketchup, soy sauce, brown sugar, rice vinegar, sriracha, Worcestershire, sesame oil, garlic and ginger. Season with a little salt and pepper. Remove 1/4 cup of the marinade to a bowl and refrigerate.
2.Using a paring knife, poke slits into each piece of chicken. Place chicken in a large bowl. Pour remaining marinade over chicken then toss to coat. Transfer to refrigerator and let marinate overnight.
3.Preheat a gas grill over medium heat. Clean grill grates and brush with vegetable oil. Grill chicken on preheated grill, turning and basting with reserved marinade occasionally, until it reaches 165 degrees in center, approximately 15 minutes.
4.Let chicken rest for 5 minutes before serving.