Pat chicken thighs completely dry with paper towels. This is the difference between crispy skin and sad, rubbery skin. Mix smoked paprika, 1/2 teaspoon salt, and pepper in a small bowl, then rub all over the chicken. Let sit at room temperature while you prep the cauliflower.

Cut cauliflower into roughly 1-inch florets. You want some flat edges - those are what get beautifully caramelized. Toss in a large bowl with 1 tablespoon olive oil, the remaining 1/2 teaspoon salt, and half the lemon zest.

Heat the remaining 1 tablespoon olive oil in a large oven-safe skillet over medium-high heat. When it shimmers, add chicken skin-side down. Do not touch for 6-7 minutes. The skin should release easily when properly seared and be deep golden brown. Flip and cook 2 minutes more, then transfer to a plate.

Pour off all but 1 tablespoon of fat from the pan. Add cauliflower in a single layer - work in batches if needed, crowding steams instead of roasts. Cook undisturbed for 4 minutes until starting to brown underneath. Stir, add garlic and capers, and cook 1 minute until fragrant.

Nestle chicken skin-side up among the cauliflower. Roast at 425F for 20-25 minutes until chicken registers 165F at the thickest part and cauliflower is tender with crispy edges. If the chicken skin needs more color, broil for 2-3 minutes - watch closely.

Transfer chicken and cauliflower to a serving platter. Drizzle with lemon juice and scatter parsley and remaining lemon zest over everything. Serve straight from the pan or piled on a platter with crusty bread to soak up the juices.