01 - Arrange the sliced onions, minced garlic, bell pepper strips, and halved cherry tomatoes evenly across the bottom of the slow cooker.
02 - Place the chicken breasts on top of the bed of vegetables 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 fully combined.
04 - Pour the balsamic mixture evenly over the chicken breasts and vegetables, ensuring everything is well coated.
05 - Cover the slow cooker and cook on low for 4–6 hours, or until the chicken is fork-tender and reaches an internal temperature of 165°F (74°C).
06 - Remove the chicken and vegetables from the slow cooker, sprinkle with chopped fresh parsley, and serve hot alongside rice, potatoes, or steamed vegetables.