Heat a little (about 2 tablespoons) olive oil in a heavy-bottomed oven-proof pot (see notes), then brown the chicken for about 2 minutes on each side. Remove the chicken from the pot onto a plate and set aside.
Add the onion to the pot and stir for a few minutes until it softens. Add the garlic and stir for a minute or so longer, then add the oregano, cinnamon and orzo and stir again for a minute or so until the orzo is coated with the juices/oil.
Take the pot off the heat and then put the chicken back into the pot, then quickly sprinkle with the paprika, allspice, salt and pepper. Finally, pour over the passata and stock and give the pot a good stir.
Bake uncovered for 30 minutes. Check and stir the pot a couple of times during cooking to stop the orzo from sticking too much. If at any time the dish looks too dry, just add an extra splash of water.
Sprinkle with fresh chopped parsley and plenty of cheese to serve. Serve with the salad, bread and a splodge of Greek yoghurt (if you like).
What pot to use
A cast iron oven-proof pot/dutch oven is great for this dish, but if you don’t have one simply use a saucepan to brown the chicken/soften the onion etc., then tip everything into a deep medium-sized baking dish before sprinkling over the spices and pouring over the tomato sauce and baking.
Don’t forget to stir the dish a couple of times while baking to stop the orzo from sticking too much to the pot. Add a splash or two of hot water towards the end of cooking if you think the dish is starting to look too dry.