In a mixing bowl, whisk together the honey, soy sauce, minced garlic, ketchup, rice vinegar, water, and red pepper flakes (if using).
Place the chicken breasts at the bottom of your crockpot, ensuring they’re well spaced for even cooking.
Pour the sauce mixture over the chicken. No need to stir; let it mingle.
Cover and cook on low for 4-5 hours or on high for 2-3 hours, until the chicken is tender and shreddable.
About 15 minutes before serving, mix cornstarch with cold water to create a slurry.
Remove the chicken and set aside. Stir the cornstarch slurry into the sauce in the crockpot. Cover and cook on high for another 10-15 minutes to thicken the sauce.
Pour the sauce over the chicken and garnish with sliced green onions before serving.
Notes
To enhance tenderness, consider marinating the chicken in the sauce for about 30 minutes before cooking.