How fancy, Gnu? Electric? Mechanical? Pan with water in it and fire below? Slow cooker/crockpot/straw box cooker?
We used to have an excellent device for the microwave oven. Essentially a plastic box with a lid and an inner which had small slits in to hold the rice. Yout put water in the bottom, below the basket and it steamed the rice very efficiently.
We later used it as a steam steriliser for baby bottles until one of the older children put something metal in it and the inner basket melted - after that rice just fell through the hole
Quack!
GtD.