01 - Arrange the chicken breasts in an even layer across the bottom of a 6-quart slow cooker.
02 - Scatter the halved baby potatoes and sliced onion evenly around and over the chicken pieces.
03 - In a small bowl, combine the olive oil, minced garlic, dried thyme, dried rosemary, paprika, kosher salt, and black pepper. Drizzle the mixture evenly over the chicken and potatoes.
04 - Pour the chicken broth into the slow cooker along the edges, taking care not to wash the seasoning off the chicken and potatoes.
05 - Cover the slow cooker and cook on LOW for 5 hours until the chicken is nearly cooked through and the potatoes are fork-tender.
06 - After 5 hours, spread the trimmed green beans on top of the chicken and potatoes. Cover and continue cooking on LOW for 1 additional hour, until the green beans are tender and the chicken reaches an internal temperature of 165°F.
07 - Serve hot, garnished with chopped fresh parsley and accompanied by lemon wedges if desired.