01 - Arrange the sliced red onion and minced garlic evenly across the bottom of the slow cooker insert.
02 - Place the chicken thighs in a single layer on top of the onion and garlic bed, ensuring even distribution.
03 - In a small mixing bowl, whisk together the balsamic vinegar, honey, chicken broth, Dijon mustard, olive oil, dried basil, dried oregano, salt, and black pepper until fully combined.
04 - Pour the prepared sauce evenly over the chicken thighs, ensuring all pieces are well-coated.
05 - Cover and cook on low setting for 6 hours or on high setting for 4 hours, until the chicken reaches an internal temperature of 165°F and is tender throughout.
06 - For a thicker sauce, carefully transfer the chicken to a plate. Pour the cooking liquid into a saucepan and simmer over medium heat for 5-8 minutes until reduced. Return the chicken to the sauce before serving.
07 - Sprinkle fresh chopped parsley over the chicken just before serving. Serve alongside rice, mashed potatoes, or steamed vegetables.