01 - Arrange the sliced onions, minced garlic, bell pepper strips, and halved cherry tomatoes evenly across the bottom of the slow cooker insert.
02 - Place the chicken breasts on top of the vegetable layer in a single even layer.
03 - In a small mixing bowl, whisk together the balsamic vinegar, chicken broth, honey or maple syrup, Dijon mustard, dried oregano, dried basil, salt, and black pepper until well combined.
04 - Pour the balsamic sauce evenly over the chicken breasts and vegetables, ensuring everything is well coated.
05 - Cover the slow cooker and cook on the low setting for 4 to 6 hours, or until the chicken is fork-tender and reaches an internal temperature of 165°F.
06 - Transfer the chicken and vegetables to a serving platter, spoon the cooking juices over the top, garnish with chopped fresh parsley, and serve hot alongside rice, potatoes, or steamed vegetables.