Season chicken thighs with salt and pepper on both sides. Lightly coat a 6-quart crockpot with nonstick cooking spray.
Arrange chicken thighs in the bottom of the crockpot.
In a medium bowl, whisk together soy sauce, apple cider vinegar, bourbon, brown sugar, garlic, and ginger. Pour the marinade over the chicken.
Cover with the lid and cook on low for 4-6 hours or on high for 3 hours.
In a small bowl, whisk together cornstarch and water to create a slurry. Pour the cornstarch slurry into the crockpot 30 minutes before the chicken is done cooking. Stir to combine.
Garnish with green onions and serve over rice.
