01 - Layer the sliced red onion and minced garlic evenly across the bottom of the slow cooker insert.
02 - Place chicken thighs in a single layer over the onion and garlic, ensuring even distribution for consistent cooking.
03 - Whisk together balsamic vinegar, honey, chicken broth, Dijon mustard, olive oil, dried basil, dried oregano, salt, and black pepper in a small bowl until thoroughly combined.
04 - Pour the prepared sauce evenly over the chicken thighs, ensuring each piece is coated.
05 - Cover and cook on low setting for 6 hours or high setting for 4 hours until chicken reaches internal temperature of 165°F and is tender.
06 - For thicker sauce, transfer cooked chicken to a plate. Pour cooking liquid into a saucepan and simmer over medium heat for 5-8 minutes until reduced. Return chicken to thickened sauce before serving.
07 - Sprinkle with fresh chopped parsley and serve immediately over rice, mashed potatoes, or steamed vegetables.