Yakitori
This recipe is from Naomi Kijima's excellent cookbook Bento Boxes: Japanese Meals on the Go. In my version, I used a chicken breast instead of a chicken thigh, and doubled the sauce quantities. It made enough for six yakitori.

1 chicken breast¹
2 tbsp mirin
2 tbsp soy sauce
2 tsp white sugar
peanut oil
yakitori skewers
green onion, sliced

Mix the mirin, soy sauce, and white sugar in a small bowl. Marinate the chicken breast in the sauce for 30 minutes. Remove the chicken from the marinade, reserving sauce. Add 6 tbsp water to the sauce. Heat peanut oil in a nonstick frying pan and brown the chicken on both sides. Pour the sauce over the chicken, cover the frying pan, and reduce heat. When chicken has been cooked through, turn heat up and reduce the sauce to a glaze. Remove chicken from frying pan and allow to cool. Cut chicken into pieces and thread onto skewers, alternating with pieces of green onion.

¹I used a boneless, skinless chicken breast because that's what I happened to have. However, the absence of skin caused the chicken to absorb the glaze. I think a skin-on piece of chicken would work better if you want the yakitori to remain shiny.