• Step 1: Place the chicken thighs in the bottom of a 6-quart slow cooker. In a medium bowl, whisk together the teriyaki sauce, brown sugar, rice vinegar, garlic, ginger, and red pepper flakes (if using). Pour the sauce over the chicken, ensuring the pieces are evenly coated.
• Step 2: Cover the slow cooker and cook on low for 6-8 hours or on high for 3-4 hours, until the chicken is cooked through and easily shreds with a fork.
• Step 3: Once the cooking time is up, remove the chicken from the slow cooker and shred it using two forks. Return the shredded chicken to the sauce in the slow cooker and stir to combine.
• Step 4: Serve the crock pot teriyaki chicken over steamed rice, garnished with sliced green onions, sesame seeds, and additional teriyaki sauce if desired.