Prepare the Chicken: In a bowl, mix olive oil, smoked paprika, garlic powder, thyme, cayenne, salt, and black pepper. Rub evenly over chicken thighs. Heat a skillet over medium-high heat and sear chicken for 4 to 5 minutes per side until blackened and cooked through. In the last minute, add lemon slices to the pan to char slightly. Finish with fresh parsley.
Roast the Broccoli: Preheat oven to 400°F (200°C). Toss broccoli with olive oil, Parmesan, breadcrumbs, garlic powder, salt, and pepper. Spread on a baking sheet and roast for 18 to 20 minutes, flipping halfway, until crispy and golden.
Roast the Carrots: On a separate baking sheet, toss carrots with olive oil, honey, salt, and pepper. Roast for 20 to 25 minutes, tossing halfway, until tender and caramelized.
Assemble the Plate: Plate blackened lemon chicken with charred lemon slices, a side of Parmesan broccoli, and honey-glazed carrots. Serve warm.