Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Scrub the Yukon gold potato and dice it into 1-inch cubes, then slice the chicken breast into even 1-inch pieces.
In a large mixing bowl, whisk together the olive oil, lemon juice, lemon zest, minced rosemary, garlic powder, sea salt, and black pepper.
Add the chicken and potatoes to the bowl, tossing thoroughly until every piece is coated in the herb marinade.
Spread the chicken and potatoes in a single layer on the prepared baking sheet, ensuring they are not overcrowded.
Roast in the oven for 15 minutes, then flip the pieces and add the asparagus spears to the tray.
Continue roasting for another 10 to 12 minutes until the chicken is cooked through and the potatoes are crispy and golden.
Remove from the oven and let rest for 3 minutes before serving to allow the juices to redistribute.