Taroudant is well known throughout Morocco for its mechoui — whole lambs or sheep slow-roasted in sealed clay underground pits called koucha. The meat cooks overnight or for many hours, emerging falling-tender. Near the souk, particularly on the big market days of Thursday and Sunday, you'll find vendors with the roasted carcasses hung up or displayed, ready to carve portions to order onto plates with cumin and flatbread.
This is fast food in the best possible sense: you point at what you want, it gets weighed and carved, and you eat standing or at a simple table. The price is per 100 grams. A full lunch costs a few dirhams. Go early — the best cuts go quickly after the lunch rush begins.