Preheat your oven to 400°F (200°C) and line a large baking sheet with unbleached parchment paper.
Wash and dice the gold potato into 1/2-inch cubes and trim the ends of the fresh green beans.
Slice the chicken breast into even 1-inch strips or bite-sized pieces to ensure they cook at the same rate as the vegetables.
In a large mixing bowl, whisk together the extra virgin olive oil, dried rosemary, garlic powder, sea salt, and black pepper.
Add the chicken, potato cubes, and green beans to the bowl, tossing thoroughly until every piece is coated in the herb oil.
Spread the mixture in a single layer on the prepared baking sheet, making sure not to overcrowd the pan so the potatoes can crisp up.
Roast for 20 to 25 minutes, tossing the ingredients halfway through, until the chicken is cooked through and the potatoes are tender and golden.
Remove from the oven and drizzle with fresh lemon juice to brighten the flavors before serving.