Preheat your oven to 400°F (200°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Wash the potato and cut it into 1/2-inch cubes, then trim the ends off the fresh green beans.
In a large mixing bowl, combine the cubed potatoes, green beans, and chicken breast.
Drizzle the olive oil over the ingredients and sprinkle with dried rosemary, thyme, garlic powder, sea salt, and black pepper.
Toss everything thoroughly to ensure the chicken and vegetables are evenly coated in the oil and herb mixture.
Spread the mixture onto the prepared baking sheet in a single layer, making sure the chicken pieces have space around them to roast properly.
Roast in the oven for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the potatoes are golden and fork-tender.
Remove from the oven and let the chicken rest for 5 minutes before slicing to ensure it stays succulent and juicy.