Igloo construction question

[thamnophis]

I'm leaning toward an igloo construction - it looks less technical and less expensive - something I could manage. The purpose of this oven will be to bake bread - hopefully 50+ loaves per week.

My question: I'm not sure how to build the first layer, the oven dome itself. The schematic in the Pompeii Oven Instructions just says, "Create the igloo using stucco lathe following the shape of the oven and insulation"

So what do I build the oven dome itself with?

Also, what is the final exterior surface made from? What is stucco exactly?

Thanks and sorry for such basic questions!

Joe