Chicken Thigh Marinade (Soy Sauce + Mirin)

Marinate the chicken
0 Combine all the ingredients for the marinade in a bowl and whisk together. 
1 Place the chicken in a bowl, baking dish or heavy duty zip-top bag. Pour the marinade over the chicken. Flip the thighs over a few times with a fork or a pair of tongs to coat them evenly in marinade.
2 If you want to cook the chicken right away, marinate at room temperature 20-30 minutes. Otherwise, store the marinated chicken in the refrigerator 12-24 hours ahead.
Grilling instructions
5 Preheat a grill to medium-high heat (400-425F; 200-220C) for direct grilling, and scrape down the grill rack with a wire brush.
6 Remove the chicken from the marinade (discard the marinade) and transfer to a plate or baking sheet. Sprinkle both sides with salt and pepper.
7 Arrange the chicken on the grill rack, skin-side up. Cook 5 minutes. Flip the chicken over and move them to a section of the grill with indirect heat. If you're cooking skin-on chicken, this will prevent the skin from scorching.
8 Cover the grill an cook until the chicken is cooked through, an additional 5-8 minutes. A digital thermometer inserted into the thickest part of the thigh should register 160-165F (70-75C). Transfer to a platter and rest 5-10 minutes before serving.
Baking instructions
10 Preheat the oven to 425 (220C) with the rack in the center. Arrange the chicken on a non-stick or foil-lined sheet pan. Bake 20 minutes for boneless thighs, or 25-30 minutes for bone-in thighs, turning the pieces over halfway through. 
Pan-Frying instructions
14 Heat 1 tablespoon neutral oil in a large nonstick or cast iron skillet over medium-high heat. Remove the chicken from the marinade and pat dry. Cook 5–7 minutes per side, until deeply browned and cooked through (165°F on an instant-read thermometer). Transfer to a plate and deglaze the pan with ¼ cup chicken broth or water, scraping up the browned bits. Spoon over the chicken before serving.
Broiling instructions
12 Position an oven rack so it's about 6 inches from the heat source. Preheat the broiler element to high for 5-10 minutes. Arrange the chicken on the rack a broiler pan, or on a grill rack set on a foil-lined sheet pan.  Broil 6-7 minutes per side, until the chicken is nicely browned.