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