Heat the butter (oil) in a saucepan, sweat the onions until colorless. Add the rice, roast until translucent, pour hot water (broth) over it, add excess salt. Cover and bring to the boil on the stove, do not stir.
Simmer in the preheated oven on the lower rack at about 140-160 ° C for 18-20 minutes. Loosen carefully with a meat fork.