Place the rice in a bowl and cover with cool water. Swirl your fingers through the rice to release some of the starch. Drain and repeat.
Drain the rice in a strainer and set aside to dry off while you chop the onion and garlic.
Heat the oil in a large pan or pot over medium heat. Fry the onion until soft then add the garlic and fry for a minute more or until soft.
Add the well-drained rice and turn the heat to medium-low. Gently toast, stirring frequently and watching carefully that it doesn’t burn, until the grains begin to take on a golden-brown color.
Remove the pan from the heat for a minute and stir in the paprika, cumin and oregano. Allow the spices to release their fragrance. We do this off the heat as paprika can burn easily.
Return the pan to the heat and add the stock, tomato sauce and salt. Cover the pan and raise the heat to medium-high to bring to a boil. Once it reaches a boil, lower the heat to low.
Allow to gently simmer for 12 - 15 minutes or until the liquid is absorbed and the rice is nearly tender. Try not to lift the lid but you can sneakily grab a spoonful if you want to check how the rice is cooking.
After 12 - 15 minutes the rice should be still a bit firm in the middle but not hard. Remove the pan from the heat and allow to steam, without removing the lid, for 5 minutes.
Finally, remove the lid and stir in the beans. Check the seasoning if it needs more salt and pepper.