Peel and finely chop the onion, peel and finely grate the garlic and deseed and roughly chop the pepper. Pick the parsley leaves and put aside, then finely chop the stalks. Roughly chop the chorizo.
Heat 1 tablespoon of oil in an ovenproof casserole pan on a medium heat. Once hot, add the onion, garlic, pepper, parsley stalks, chorizo and paprika. Cook for around 5 minutes, or until starting to soften, stirring regularly.
Add the rice, then stir everything around until the rice is coated in all the lovely flavoured oil. Pour in the passata and stock, then add the zest and juice of 1 lemon.
Submerge the chicken in the sauce, bring to the boil, then reduce to a simmer. Scrunch up a wet piece of greaseproof paper, then open it out and place on top of the bubbling dish. Put a tight fitting lid on top, then place in the oven to cook for 45 minutes to 1 hour, or until the rice is tender and the chicken is cooked through. Loosen with a splash of boiling water, if needed.
Finely chop the parsley leaves, then sprinkle over the top. Cut the remaining lemon into wedges for squeezing over. Delicious served with a crisp green salad.