Wash and chop the mushrooms coarsely.
Pour oil in a pot and once it heats up, add the mushrooms.
Braise them to a golden color and add the finely chopped onions.
Stir periodically and once the onions soften, add the rice, spices and salt.
Pour in the hot broth and grated tomatoes.
Boil on low heat until the rice is fully cooked.