Mix together the soy sauce and Sriracha sauce and pour over chicken. Marinate in the refrigerator 30 minutes to 2 hours, turning once.
Remove chicken from marinade and grill over medium-high heat for 6-7 minutes per side, or until cooked. (See Notes for more details and cooking options.)
TO MAKE OPTIONAL POURABLE SAUCE: Meanwhile if you'd like a pourable sauce for the table, pour the used marinade into a small saucepan and bring to a boil over medium-high heat and boil for 10 minutes. Alternately, just mix up more sauce to pass and throw out the marinade.
Notes
*To use bone-in chicken, just increase the cooking time.Cooking Options:
Grill: Heat grill to medium-high and grill thighs 6-7 minutes on each side until internal temperature is 165 to 180 (unlike breasts, it's hard to overcook chicken thighs).
Bake: Preheat your oven to 400 degrees. Bake the chicken in a roasting pan or sheet pan for 25-30 minutes for boneless (45 minutes for bone-in) or until juices run clear and the internal temperature in a thick part is 165 to 180 degrees.
Pan Fry in Skillet: Over medium-high heat, cook one side of the thighs for 6-7 minutes and then flip to finish cooking to an internal temperature of at least 165 degrees.