In a small bowl, combine the soy sauce, Worcestershire sauce, brown sugar, ginger, and garlic.
Place the chicken thighs in a baking pan then use a brush or spoon and evenly pour sauce over them, reserving about 1 Tbsp of sauce.
Let these sit for about 2-3 hours.
Warm the grill to medium-high heat when ready to cook. Spray the grill pan with non-stick cooking spray, then place the chicken thighs on the pan and grill evenly on both sides until they reach at least 165*.
Serve them with additional sauce and green onions.