Add the boneless skinless chicken thighs to your slow cooker.
Combine the soy sauce, honey, ketchup, minced garlic, fresh minced ginger, sesame oil, and crushed red pepper flakes in a bowl and whisk thoroughly.
Pour this sauce evenly over the chicken in the slow cooker.
Cover and let it cook on low heat for 3 to 5 hours or on high heat for 2 to 3 hours until the chicken is very tender and has reached 165°F internally.
Avoid lifting the lid during cooking to ensure optimal tenderness and proper cooking time.
Using two forks, remove the chicken from the slow cooker and shred it well.
In a separate small bowl, blend the water and cornstarch to create a slurry.
Mix the shredded chicken and cornstarch slurry back into the sauce in the slow cooker.
Cook on high for an additional 15 to 20 minutes until the sauce thickens slightly.
Serve the honey garlic chicken over rice, noodles, or your favorite vegetables and garnish with sesame seeds and sliced green onions if you like. Be sure to spoon extra sauce over each serving for full flavor.