Preheat your oven to 400°F (200°C) and line a large sheet pan with parchment paper.
Slice the baby potatoes into halves and the carrots into 1/2-inch thick rounds.
Place the chicken breast, potatoes, carrots, and broccoli florets on the prepared sheet pan.
Drizzle the avocado oil over the chicken and vegetables, then sprinkle evenly with garlic powder, dried rosemary, sea salt, and black pepper.
Toss the vegetables to coat thoroughly and ensure the chicken is seasoned on both sides.
Arrange everything in a single layer, ensuring the chicken has space around it to roast evenly.
Roast in the center of the oven for 20 to 25 minutes, or until the chicken reaches an internal temperature of 165°F and the potatoes are fork-tender.
Remove from the oven and let the chicken rest for 5 minutes before slicing to keep it juicy.
Plate the sliced chicken alongside the roasted vegetables and enjoy immediately.