In some parts of the world, they are called Upesi Stoves. I'm not sure of the Khmer name for this particular stove, here in Cambodia. But, they are constructed similar to the stoves in this resource.
Basically, upesi stoves are formed from clay, then fired. Here in Cambodia, charcoal is most often used as the combustible fuel in upesi stoves. Although, wood is used on the odd occasion. - Paul
How To Make An Upesi Stove 1995
How To Make An Upesi Stove, By Vivienne Abbott, Clare Heyting, And Rose Akinyi