Preheat the oven to 400°F (200°C).
In a small bowl, mix the juice of half a lemon, minced garlic, chopped fresh thyme, chopped rosemary, salt, and pepper.
Pat the chicken breast dry and rub the lemon-herb mixture evenly over it.
Place the chicken on a baking sheet lined with parchment paper.
Roast the chicken in the oven for 20-25 minutes, or until the internal temperature reaches 165°F.
While the chicken is roasting, heat olive oil in a sauté pan over medium heat.
Add the green beans to the pan, seasoning lightly with salt and pepper, and sauté for about 5-7 minutes until they are tender but still crisp.
Serve the roasted chicken sliced alongside the crispy green beans, garnished with a drizzle of any remaining pan juices and a squeeze of fresh lemon.