1Pat chicken thighs dry and arrange in the slow cooker in a single layer.
2In a small bowl, whisk together minced garlic, ginger, honey, soy sauce, and rice vinegar until smooth.
3Add sliced onion to the slow cooker around the chicken, then pour the honey-garlic mixture over everything.
4Cover and cook on low for 6–7 hours (or high for 3–4 hours) until chicken is very tender and cooked through.
5In a small cup, mix cornstarch with 2 tbsp water until smooth. Stir it into the sauce in the slow cooker.
6Cook uncovered on high for 10–15 minutes until the sauce thickens slightly.
7Taste and adjust seasoning if needed. Serve chicken and sauce over white rice or noodles, garnished with chopped scallions and sesame seeds if desired.