Heat a large, deep frying pan or paella pan until hot, then add the oil and onion and cook for 5 minutes until softened. Stir in the garlic and cook for 30 seconds, then add the paprika and rice and cook for a further 1 minute, stirring until well coated.
Add the pepper and artichokes, then stir in the saffron and chopped tomatoes. Pour in the stock and bring to the boil, then reduce the heat and simmer for 12 minutes or until most of the liquid has been absorbed.
Stir the rice to evenly distribute the vegetables, then reduce the heat to very low and cook for 5 minutes or until all the liquid has been absorbed and the rice is tender. Season to taste and scatter with chopped parsley before serving.