Wash and boil the rice in salted water, then rinse with cold water and drain. In a Teflon pan, heat enough oil to cover the bottom.
Fry the onion that you've cut into thin crescents and the carrots, cut into sticks, for 1-2 minutes. Add the garlic and mushrooms cut into thin slices, then fry for another 2 minutes, stirring constantly.
Stir for a few minutes until the rice is seasoned and remove it from the heat.