Preheat your oven to 425°F (220°C) and line a large rimmed baking sheet with parchment paper for easy cleanup.
Wash and dice the gold potato into uniform 1/2-inch cubes to ensure even roasting.
Mince the garlic clove and finely chop the fresh rosemary and thyme leaves.
In a mixing bowl, toss the potato cubes with half of the olive oil, half of the salt, and half of the black pepper.
Spread the potatoes in a single layer on the prepared baking sheet and roast for 10 minutes.
While potatoes are roasting, whisk together the remaining olive oil, lemon zest, lemon juice, minced garlic, rosemary, thyme, and the rest of the salt and pepper in a small bowl.
Coat the chicken breast thoroughly with the lemon-herb mixture.
Carefully remove the baking sheet from the oven, slide the potatoes to one side, and place the chicken breast on the other side.
Return the sheet to the oven and roast for another 15-20 minutes, or until the chicken reaches an internal temperature of 165°F and the potatoes are fork-tender and browned.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep the juices intact, then serve alongside the crispy potatoes.