Preheat your oven to 425°F. While it heats, prepare all your ingredients: pat the chicken breasts dry with paper towels (this helps them brown better), cut potatoes into 1-inch cubes, cut broccoli into florets, and zest and juice the lemon. Combine all the dried seasonings (Italian seasoning, thyme, onion powder, and paprika) in a small bowl to create a unified spice blend. I find mixing the spices together first ensures even distribution across all components rather than seasoning each ingredient separately.

Season the dried chicken breasts generously with kosher salt, freshly ground black pepper, and about half of your spice blend from Step 1, drizzling with 1 tablespoon olive oil as you season. In a separate bowl, toss the cubed potatoes with 1 tablespoon olive oil, kosher salt, black pepper, and the remaining half of your spice blend. Spread the seasoned potatoes in a single layer on your baking sheet, then arrange the seasoned chicken breasts on top of or next to the potatoes (they can be close but shouldn't overlap). If desired, scatter lemon slices around the pan for subtle citrus flavor during roasting.

Place the baking sheet in your preheated 425°F oven and roast for 20 minutes. The chicken will begin to cook through and the potatoes will start to soften and develop golden edges. While this is roasting, prepare the broccoli by tossing it in a bowl with 1 tablespoon olive oil, kosher salt, and freshly ground black pepper—have this ready to add when you pull the pan from the oven.

Carefully remove the baking sheet from the oven after 20 minutes. The chicken should be mostly cooked but not yet fully done, and the potatoes should be getting tender. Add the prepared broccoli from Step 3 to the baking sheet, arranging the florets around the chicken and potatoes so they roast evenly. Return to the oven and roast for another 10 to 15 minutes until the chicken is cooked through (165°F internal temperature), the potatoes are tender and golden, and the broccoli is bright green with slightly crispy edges.

Remove the baking sheet from the oven and let the chicken rest for 5 minutes before serving—this allows the juices to redistribute throughout the meat, keeping it moist and tender. I always let my chicken rest even though it's tempting to dive right in; it makes a noticeable difference in texture. Transfer the chicken, roasted potatoes, and broccoli to serving plates, garnish with fresh chopped parsley and a squeeze of fresh lemon juice if desired, and serve while hot.