In a medium bowl, whisk together the minced garlic, grated ginger, onion powder, rice vinegar, brown sugar, sesame oil, soy sauce, chili sauce, and ketchup until the sugar dissolves.

Add the cubed chicken to the marinade, ensuring each piece is coated. Let sit for 15 minutes at room temperature or up to 3 hours in the refrigerator.

Soak bamboo skewers in water for at least 30 minutes. Thread 3-4 marinated chicken pieces onto each skewer.

In a small saucepan, pour the reserved marinade and add ¼ cup of water. Simmer over medium heat for 2-3 minutes until thickened.

Preheat your grill to medium-high heat. Grill the skewers for 4-5 minutes, flipping every 2 minutes and brushing with sauce in the last 2 minutes.

Remove skewers from the grill and serve hot alongside steamed rice or stir-fried noodles, drizzling with remaining sauce.