Start by boiling water and when it is ready pour the rice inside, then leave it cook.
Then take a large saucepan and pour in the olive oil and then pour the leek and fry for 2 minutes, then pour the red beans, the tomato paste ,the water, the salt and the pepper and mix well. Optionally add a Bouillon cube for extra tastiness
When the rice is done pour it on a colander and let it there for some minutes. If the sauce with the beans is thick, then it means it is done, remove it from the heat and pour it in a large bowl, pour the rice in the bowl and mix well to spread the sauce everywhere and serve the food when the sauce is still warm.