Pour in the olive oil and garlic and let it brown without burning, add the rice and let it fry, stirring until the rice is translucent. Pour in the boiling water and season with salt. Cover with the lid and cook the rice for about 13 minutes or until total absorption of the liquid.
In the meantime, pour the black beans into a sieve, pass with plenty of running water and then drain.
Peel and chop the red onion, Chop the coriander (leaves and stalks).
When the rice is cooked, add the black beans, the onion and the chopped coriander.
Drizzle with lemon juice and stir with a fork until well mixed.