Combine the tomato paste, half of the olive oil, paprika, chilli powder and lemon juice in a large bowl and mix well
Add the chicken to the bowl and toss to coat completely
Place the remaining oil in a large heavy-based frying pan and add the chicken skin side down
Cook over medium heat for 6-8 minutes until the chicken skin renders and starts to brown, then transfer to a tray
Add rice to a bowl of water until completely covered
Dice the red onion and finely dice the carrot, then add to the pan and cook for 3 minutes until softened
Deglaze the pan with some stock, scraping off the fond from the bottom
Add the cinnamon stick and cumin, season with salt and cook for 2 minutes until aromatic
Drain the rice, add it to the pan and stir through the vegetables
Add the remaining stock and return the chicken to the pan
Bring to a simmer, reduce heat to very low, cover and cook for 15 minutes
Remove the chicken and set aside, then discard the cinnamon stick
Stir the rice, add the spinach, cover and let sit for 2 minutes
Uncover and stir the spinach through the rice, then serve with chicken on top
