Tajine is earlier much used, no matter what form they have, the intention is that the food will cook equaly without burning or drying.
A tajine is a thick clay pot that is many times used in North Africa for stews with the same name. The Tajine is traditionally used on an open fire. You almost don't need water because the lid condenses and then drips on the food. The high shape keeps the lid cool on the top, so it can be lifted without a potholder.