Heat the oil in a medium saucepan with a tight-fitting lid and fry the chicken and sausage for 3 minutes.
Add the onion and celery, season well and fry for 5 minutes, or until softened. Add the garlic and pepper and cook for a further minute. Add the tomatoes and cayenne and cook for 2 minutes, then add the rice and stir well.
Pour over the stock, bring to the boil, put the lid on, turn the heat down as low as it will go and cook for 12 minutes.
Turn off the heat and leave the rice to stand for 12 minutes. Take off the lid, fluff up the rice and serve immediately, garnished with the parsley, if using.
