Heat the oil in a pot. Add the onion and garlic and cook until they are soft but not browned. Stir in the tomatoes and cook for 5 minutes. Add the rice and mix with the vegetables.
Add water in two and a half times the amount of rice and bring to the boil. Cover the rice and cook over low heat until it is soft and has absorbed all of the liquid. Stir in parsley, salt and pepper to taste.