Heat oil in a pot over medium heat. Add the sliced onion and sauté until golden brown.

Remove the onion from the pot and set aside.

Add butter, rice, and yellow lentils to the pot. Stir for 5 minutes over low heat.

Add water and salt, then stir to combine.

Let the rice absorb the water.

Cover and cook over low heat until the rice is fully cooked.

Serve the dish topped with the fried onions.