In a medium-sized bowl whisk sauce ingredients together; honey, mirin, soy sauce, rice vinegar, and sesame oil.
Add chicken to a large resealable plastic bag. Add minced garlic and ¼ cup of the sauce mix. Seal bag, removing excess air.
Use your hands to distribute the sauce and garlic evenly around the chicken. Leave at room temperature on the counter to marinate while making the sauce. If you're not going to cook the chicken right away, transfer to the refrigerator for up to 1 day for marination.
Add remaining sauce to a medium-sized skillet.
Turn heat to medium-high and allow to cook and reduce by half until slightly thickened, about 8 to 10 minutes. About just over ⅓ cup sauce remaining. You want the sauce to be thick enough to glaze and stick to the chicken and not be runny. Set aside.
Heat grill over medium-high heat. Add a small amount of vegetable oil on a folded piece of paper towel, and then carefully grease the grill grates.
Once the grill is nice and hot, add the chicken pieces. Cook uncovered on each side until no longer pink (160-165°F), about 4-6 minutes on each side, depending on the thickness of the chicken.
Flip over and baste the chicken with sauce. At the end of cooking brush with more sauce before serving.
In a small bowl mix sesame seeds, chives, red pepper flakes, and lemon zest. Sprinkle on top of chicken. Serve with lemon wedges if desired.
Chicken thighs can be substituted for chicken breasts. Cook about 5 minutes on each side, or until internal temperature reaches (160-165°F).
You can cook the chicken in a large saute pan over medium-high heat with 1 tablespoon heated olive oil if you do not have a grill.