Prepare grill and heat to 350 degrees.
Lightly season chicken wings with salt and freshly ground black pepper.
Place on grill and cook for 45 minutes, turning throughout the cooking time to ensure even browning. While wings cook, prepare the sauce.
In a large size microwavable bowl, whisk together the sesame oil, garlic, and ginger. Microwave until bubbly and fragrant, about 45 seconds.
Whisk in 1/4 cup water, sugar, gochujang, and soy sauce until smooth. Set aside.
Pull wings off grill and toss in sauce mixture. Place back on grill and cook for 2-3 minutes on high heat to crisp, reserving any remaining sauce. Remove wings from grill and place on serving dish. Drizzle remaining sauce over wings, sprinkle with toasted sesame seeds and finely chopped chives.