If using wooden skewers, soak in water for at least 30 minutes before using to prevent them from burning on the grill. We prefer metal skewers.
In a small bowl combine all the marinade ingredients and whisk them together.
Cut chicken thighs into 1 inch cubes. Add to the bowl with the marinade, stir to coat well, cover, and let sit at room temperature for 30 minutes to marinate. If preparing in advance, you can marinate in the refrigerator for up to 12 hours and let sit out at room temperature for 30 minutes before grilling.
Once the chicken has finished marinating, lightly oil the grill grate and preheat the grill to medium-high, about 400 degrees Fahrenheit. Thread cubed chicken,green bell pepper, red bell pepper, and red onion onto the skewers.
Place skewers on preheated grill and turn every 3-4 minutes, until browned, beginning to char in spots, and fully cooked through, internal temperature of the chicken needs to be 165 degrees Fahrenheit — about 10-15 minutes.
Take off the grill and serve immediately.