Pat the chicken thighs dry with paper towels, then season both sides with 1 1/2 tsp salt and 1/2 tsp black pepper (adjust to taste). Drying the skin is essential so it crisps during searing — moisture is the enemy of a golden, crackling skin.

Make the citrus-garlic marinade: in a bowl whisk together 2 tbsp of the olive oil, 2 tbsp lemon juice, the crushed garlic, and 1 tsp of za'atar. Reserve 2 tbsp of this mixture for the warm quinoa later. Place the chicken in a shallow dish, pour over the marinade, and turn to coat. Let rest at room temperature 15–20 minutes (or refrigerate up to 2 hours). Marinating briefly brightens the chicken with citrus and helps the garlic infuse flavor without cooking it off.

Preheat oven to 425°F (220°C). Toss the halved Brussels sprouts with 1 1/2 tbsp olive oil, 1/2 tsp salt and 1/4 tsp black pepper. Spread them cut-side down on a rimmed baking sheet. Roasting at a high temperature caramelizes the cut surface and develops nuttiness — that caramelization is a major flavor driver here.

Place a large oven-safe skillet (cast iron preferred) over medium-high heat. Add 1/2 tbsp olive oil and, once shimmering, add the chicken thighs skin-side down. Sear without moving 4–5 minutes until the skin is deep golden brown. Searing renders fat and creates the Maillard crust that gives the chicken savory depth. Flip and sear the other side 1–2 minutes.

Transfer the seared chicken to the baking sheet next to the Brussels sprouts (or return skillet to oven if there’s room). Roast in the preheated oven 14–18 minutes, or until an instant-read thermometer in the thickest part reads 165°F (74°C). Roasting after sear finishes cooking through gently and ensures the skin stays crisp rather than steaming in the pan.

While the chicken roasts, rinse the quinoa under cold water in a fine-mesh sieve to remove the natural bitter coating (saponin). In a medium saucepan, combine the rinsed quinoa and 480 ml (2 cups) water and a pinch of salt. Bring to a boil, reduce to a simmer, cover and cook 12–15 minutes until the water is absorbed and the germ has popped out as a white spiral. Rest, covered, off the heat 5 minutes — resting lets the steam finish cooking the grain and gives a fluffier texture.

While the quinoa finishes, place the baking sheet with Brussels and chicken back in the oven if not already there; the Brussels will roast 20–25 minutes total (they can finish in the oven with the chicken). If any Brussels are done earlier, remove them to prevent over-browning. High-heat roast plus some space between pieces prevents steaming and encourages crispy edges.

Prepare the pomegranate‑za'atar dressing: in a small bowl combine remaining 4 tbsp olive oil, 2 tbsp lemon juice, remaining 3 tsp za'atar, the pomegranate seeds (reserve a tablespoon for garnish), the orange segments (toss gently so they keep shape), chopped parsley, and a pinch of salt and pepper. Stir to combine. This dressing is meant to be bright and juicy — the oil bridges the citrus and pomegranate while za'atar adds thymey, sesame notes.

When quinoa is ready, fluff with a fork and stir in the 2 tbsp of reserved lemon-garlic marinade and a pinch of salt. If the chicken pan released juices while searing, spoon a tablespoon or two into the quinoa — those juices carry deep roasted flavor and tie the components together.

Remove the chicken from the oven and let rest 5–7 minutes before slicing. Resting allows juices to redistribute so the meat stays moist when cut.

To serve: divide the warm quinoa among 4 plates, arrange roasted Brussels sprouts alongside, place a whole or sliced chicken thigh on each, then spoon the pomegranate‑za'atar dressing and orange segments over the plate. Finish with the reserved pomegranate seeds and a sprinkle of chopped parsley and extra za'atar if desired. The hot-cold contrast (warm quinoa/roasted vegetables and cool citrus/pomegranate) creates a lively texture and flavor interplay.