First, wash the lentils and cook them using a pot filled with water, with a closed lid, leaving a small aperture
Second, once the lentils are cooked, using a skimmer spoon, pour them in a food mill placed over a bowl. Turn the crank to peel the lentils and obtain a purée. Throw away the waste that will remain in the food mill
Then, cut the onion in small pieces
In a pan add the vegetable oil and cook the onion on medium heat until it changes color
Next, pour the newly obtained purée in a pot on medium heat, along with the cooked onion, the rice, salt
Now stir frequently until the rice is cooked
Finally remove the pot from the heat, and pour your freshly cooked meal in hollow plates
You can eat it hot or wait for some time until its texture gets more firm