Preheat your oven to 400°F and line a large baking sheet with parchment paper.
Cut the gold potato into 1-inch cubes and trim the ends of the green beans.
Mince the garlic and finely chop the fresh rosemary.
In a large bowl, whisk together the olive oil, lemon juice, minced garlic, rosemary, sea salt, and black pepper.
Add the chicken breast, cubed potatoes, and green beans to the bowl, tossing until everything is thoroughly coated in the herb mixture.
Spread the ingredients in a single layer on the prepared baking sheet, ensuring the chicken has enough space to roast evenly.
Bake for 20-25 minutes, or until the chicken reaches an internal temperature of 165°F and the potatoes are fork-tender.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep it juicy.