Preheat your oven to 400°F and line a large baking sheet with parchment paper for easy cleanup.
Scrub the yellow potato and chop into 1-inch cubes, then peel and slice the carrots into half-moons.
Place the chicken breast, cubed potatoes, and sliced carrots on the prepared baking sheet.
Drizzle the olive oil over the chicken and vegetables, then sprinkle evenly with sea salt, black pepper, dried rosemary, and garlic powder.
Toss the vegetables to coat thoroughly and ensure the chicken is well-seasoned on both sides.
Roast in the oven for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the potatoes are fork-tender.
During the last 5 minutes of roasting, add the frozen peas to the tray to warm through.
Let the chicken rest for 5 minutes before slicing to keep it juicy, then serve alongside the roasted vegetables.