Bring a large pot of water to a boil. Add rice and salt; cook for 6 minutes. Drain in a colander. Rinse rice and drain again.
Put oil in the bottom of the pot and place potato slices in a single layer over top. Pour cooked rice on top of potato slices, cover, and cook over low heat until rice and potatoes are tender, 20 to 30 minutes.
Invert carefully onto a serving plate so sliced potatoes are on top of rice.