This natural building kitchen includes a barrel oven surrounded in cob to help hold the heat. Note the tiles embedded in the cob and other nice touches throughout the kitchen.
Image source: BIOARQUITECTURA Y ARQUITECTURA BIOCLIMATICA – EJEMPLOS (high res version)
Build another outside for summer cooking?
I wondered why they put the cob oven in the kitchen. By the looks of the roof (no insulation) this home is probably in a hot climate. Best to put the oven outside or have two ovens like you say.
It would be pretty easy to build something like this at very low cost. Note the simple materials — it’s mostly wood poles and earth.