Heat oven to 500° F. Place empty sheet pan in the oven while it heats.
Mix together.
Season chicken thighs with the spice rub. Let it rest uncovered (skin-side up) at room temperature while the oven heats up. Drizzle olive oil evenly across the skin.
Transfer the chicken thighs, skin-side down, to the preheated sheet pan. Lower heat to 425° F and continue roasting for 15 minutes.
Toss until vegetables are evenly coated.
Remove the pan from the oven. Flip the chicken so it’s skin-side up, and scatter the preserved lemon peel in the pan drippings. Add broccoli mixture, distributing it evenly amongst the chicken thighs. Continue roasting for another 10 minutes.
Scatter the parmesan evenly over the dish, and check the chicken for doneness (target temperature is 165° F in the thickest parts). Continue roasting for another 5 to 10 minutes or until the chicken is done.
Remove the sheet pan from the oven and let the chicken rest for 10 minutes.