In the central Iranian city of Isfahan, Biryani is made with cooked mutton or lamb, which is stewed and minced separately, and then grilled in special small round shallow pans in an oven or over a fire. The meat is generally served with powdered cinnamon in a local bread, usually “nan-e taftoun”, but also occasionally “nan-e sangak”.

You can see some pictures taken during a festival of biryani cooking held in Isfahan:

Source:
Tasnim News
wikipedia