Preheat the oven to 200°C fan (220°C conventional).
Prepare the base: In a large roasting tray, toss the sliced onions and shredded cabbage with 2 tbsp olive oil. Spread evenly across the tray.
Add the orzo: Sprinkle the orzo over the vegetable base.
Season the chicken: Place the chicken thighs on top of the orzo and vegetables. Drizzle with a little olive oil, then sprinkle over the seasoning mix, chopped garlic, thyme sprigs, and parsley. Massage everything together with your hands to coat evenly.
Add the lemon & stock: Grate the lemon zest over the chicken, squeeze over the juice of half a lemon, and tuck the lemon slices around the chicken. Pour the chicken stock around the chicken, making sure the orzo is submerged.
Bake covered: Cover the tray tightly with foil and bake for 1 hour.
Final bake: Remove the foil, scatter over more fresh parsley, and return to the oven for another 20 minutes until the chicken skin is crispy and golden.
Serve: Spoon onto plates, making sure to scoop up the orzo and caramelized onions. Enjoy!
