You can create an incredibly simple house with a stone base. Of course, you need to shape the stones you use to fit perfectly. Before you start your stand, mark the area you want to cover and tessellate it. After that, you can build the circular structure of your pit.
One of the simplest ways is to make a chimney with bricks. You can place them in any shape and then fill the inside with stones. Remember to place a grill on the grill and make sure your grill is large enough to not fall out.