Preheat your oven to 425°F.
Pat the chicken breast dry and season on both sides with salt, pepper, dried rosemary, dried thyme, and garlic powder.
In a bowl, toss the diced potatoes with 1 tsp olive oil, salt, and pepper. Spread them out on a baking sheet.
Roast the potatoes in the oven for about 10 minutes to get a head start on crispiness.
Place the seasoned chicken breast on the baking sheet with the potatoes. Drizzle the remaining 1 tsp olive oil over the broccoli florets and season lightly with salt and pepper.
Add the broccoli to the baking sheet alongside the chicken and potatoes.
Roast everything together in the oven for 18-22 minutes, or until the chicken is cooked through (internal temperature reaches 165°F), the potatoes are crispy on the edges, and the broccoli is tender with slight browning.
Remove from the oven, let rest for a few minutes, then serve warm.