In a medium mixing bowl, combine the honey, low-sodium soy sauce, minced garlic, grated ginger, rice vinegar, black pepper, and red pepper flakes (if using). Whisk thoroughly until the mixture is well blended.
Line the bottom of your slow cooker with the bone-in chicken thighs, making sure they are placed skin-side up. Pour the honey garlic sauce generously over the chicken, ensuring each piece is well coated for maximum flavor.
Carefully pour the chicken broth around the chicken thighs; this will create a wonderfully flavored sauce without diluting the honey-garlic mixture on the chicken.
Secure the lid on the slow cooker and set it to cook on low for 6 hours, or on high for 3 hours, until the chicken is fork-tender and cooked through.
Once the cooking time is complete, gently lift the chicken from the slow cooker and transfer it to a serving platter. This will help retain the juices in the slow cooker.
For a thicker sauce, consider transferring the sauce from the slow cooker to a small saucepan. Bring it to a simmer over medium heat and cook until reduced by half, stirring occasionally to avoid burning.
Drizzle the thickened sauce generously over the chicken thighs before serving. Garnish with the sliced green onions and a sprinkle of sesame seeds for an attractive finish.
Notes
For an appealing presentation, serve the chicken thighs over a fluffy bed of steamed jasmine rice or quinoa, paired with steamed broccoli or a vibrant fresh green salad.