1. Prick the chicken with a fork all over and place in a Ziploc bag. Combine the garlic with the miso in a small bowl. Add the mixture to the bag and rub it all over the chicken from the outside. Chill in the refrigerator for at least 4-6 hours, preferably overnight.
2. About 3 hours before cooking, add the soy sauce and mirin to the bag and mix well. Keep in the refrigerator until ready to cook.
3. Line a baking pan with aluminum foil and coat with oil. Place the chicken on the foil skin side down first. Set the broiler to high and broil for until nicely browned, about 10 minutes.
4. Flip the chicken and broil for 10 more minutes. (The cooking time will vary depending on the oven.) Remove from the oven and serve immediately.
Image Credit: Namiko Chen