Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper for easy cleanup.
Wash the gold potatoes and cut them into uniform 1-inch cubes, then trim the ends off the fresh green beans.
Cut the chicken breast into bite-sized pieces to ensure they cook evenly alongside the vegetables.
Mince the garlic cloves and finely chop the fresh rosemary leaves.
In a large mixing bowl, combine the chicken, potatoes, and green beans with the olive oil, minced garlic, rosemary, sea salt, black pepper, and onion powder.
Toss everything thoroughly until the ingredients are well-coated in the oil and seasonings.
Spread the mixture in a single layer on the prepared baking sheet, ensuring space between the pieces for optimal roasting.
Roast for 25 to 30 minutes, tossing halfway through, until the chicken is cooked through and the potatoes are fork-tender and golden brown.
Serve immediately while hot and fragrant.