In a large bowl, whisk together vegetable oil, sesame oil, minced garlic, ginger, dark soy sauce, and honey until blended. Add the chicken breasts and coat them well in the marinade. Cover the bowl and refrigerate for a minimum of 1 hour, though marinating overnight will amplify the flavor.

Preheat your grill or stovetop griddle to medium-high heat. After marinating, carefully thread the chicken, red bell pepper pieces, and onion chunks onto the skewers, alternating for a vibrant presentation.

Place the skewers on the preheated grill and cook for 8-10 minutes, turning occasionally to achieve a nice char. Brush with reserved marinade halfway through grilling.

Once cooked through, remove the skewers from the grill and let them rest for a couple of minutes. Sprinkle sesame seeds and roughly torn coriander on top before serving.