Preheat your oven to 400°F.
In a small bowl, mix the olive oil, lemon juice, dried herbs, salt, and pepper.
Place the chicken breast on a baking tray and brush with half of the lemon herb mixture. Let it marinate for 10-15 minutes if possible.
Peel and cube the sweet potato into bite-sized pieces. Toss with a bit of olive oil, salt, and pepper.
Trim the ends of the green beans and toss lightly with salt, pepper, and a drizzle of olive oil.
Arrange the sweet potato cubes on one section of a baking sheet and the green beans on another section. Place the marinated chicken breast on the tray as well.
Roast everything in the oven for 20-25 minutes, or until the chicken is fully cooked (internal temperature reaches 165°F), the sweet potatoes are tender and slightly crispy, and the green beans are roasted.
Remove from the oven, let it rest for a couple of minutes, and serve warm.