Combine the coriander, oil, chilli sauce, sugar, soy sauce, garlic, ginger, onions and 1/2 teaspoon salt in a mini food processor or blender and process until smooth.
Drain the skewers and thread a piece of chicken onto each skewer. Place the skewers in a large nonreactive baking dish and rub with the marinade mixture. Cover and marinate in the refrigerator 1 to 2 hours.
Preheat a grill or grill pan over medium-high heat. Remove the skewers from the baking dish and discard the marinade. Cook the chicken, turning once, until well charred and cooked through, 4 to 6 minutes per side. Serve with your favorite dipping sauce.