Preheat the oven to 400°F (200°C).
Toss the green beans in 1 teaspoon of olive oil, salt, and pepper, then spread them out on a baking sheet.
Peel (if desired) and cut the sweet potato into cubes. Toss the cubes with the remaining olive oil, salt, pepper, and minced garlic.
Place the sweet potatoes on a baking sheet and roast in the oven for about 25-30 minutes, or until tender and slightly caramelized.
Season the chicken breast with salt, pepper, chopped rosemary, and thyme. Optionally, lightly sear the chicken in a hot pan for 1-2 minutes per side to lock in flavor.
Roast the seasoned chicken in the oven alongside the vegetables for about 18-20 minutes, or until the internal temperature reaches 165°F (74°C).
Add the green beans to the oven during the last 10-12 minutes of cooking to keep them crispy.
Remove all items from the oven once done and let the chicken rest for a few minutes before slicing.
Plate your herb-roasted chicken with a side of roasted sweet potatoes and crispy green beans, and enjoy!