Preheat oven to 220°C / 430°F.
Pulse the whole canned tomatoes in a food processor or blender until smooth.
Add chicken to a Dutch oven or oven-proof cooking pot. Drizzle with olive oil and season with salt and pepper. Roast the chicken for 30 to 40 minutes until golden on top. Then remove the chicken, set it aside, and place the Dutch oven on the stovetop.
Drop the oven's temperature to 180°C / 360°F.
Saute the onion and garlic in the chicken fat, if necessary add a bit more oil. Add also the bay leaf.
Add the orzo and saute for a minute.
Add the tomato paste, canned tomatoes, allspice, a pinch of cinnamon, and season with salt and pepper. Cook for about 2 minutes and pour in 750 ml hot water or stock. Add also the chicken on top.
Bake. Close the Dutch oven (or cooking pot if that's what you are using) and place it back in the oven. Cook for about 40 minutes (stirring the orzo 1-2 times meanwhile so it doesn't stick at the bottom).
Raise the oven's temperature to 200°C / 390°F.
Uncover the food and cook for 10 minutes more. Until orzo absorbs most of the sauce. If too sticky add a splash of more water.
Serve warm with grated cheese on top and freshly ground pepper.