In a small bowl, whisk together miso paste, sesame oil, olive oil, mirin, Sriracha, soy sauce and salt until nice and smooth.
Place the chicken in a large ziplock bag and pour the prepared marinade. Squeeze out the air, as you close the bag. Massage the marinade into the meat to distribute it evenly. Marinade for 20-30 minutes. If you’re cooking right away, keep it at room temperature. If not cooking within 30 minutes, refrigerate until 30 minutes prior to cooking.
Preheat the oven to 350°F (175°C).
Place the chicken in one layer on baking pan. Bake for about 35 minutes, or until internal temperature registers 170°F (76°C).
Garnish with sliced green onion and sesame seeds. Serve with steamed rice, or vegetables of your choice for a complete meal.