Place the chicken thighs in a single layer in the bottom of the slow cooker.
In a medium bowl, whisk together the bourbon, honey, soy sauce, ketchup, brown sugar, apple cider vinegar, minced garlic, ground ginger, and red pepper flakes until smooth. Pour this sauce evenly over the chicken.
Cover and cook on low for 5 to 6 hours or on high for 3 hours, until the chicken is very tender and fully cooked.
Remove the chicken thighs from the slow cooker and set them aside on a plate. Transfer the cooking liquid to a small saucepan.
In a small bowl, whisk the cornstarch and cold water together. Stir the slurry into the saucepan with the cooking liquid. Bring to a simmer over medium heat, stirring frequently, and cook for 3 to 4 minutes until the sauce thickens and becomes glossy.
Return the chicken to the slow cooker and pour the thickened sauce over the top. Gently toss to coat every piece.
Serve over steamed white rice, garnished with sesame seeds and sliced green onions. The sweet, savory, bourbon-laced glaze on this chicken is absolutely addictive.