The short answer
At a good desert camp, dinner is laid in a large tent or around an open fire and usually runs to four courses: harira soup, a pastilla or salad starter, a slow-cooked tagine or mechoui, then almond pastries with mint tea. Breakfast brings breads, eggs and tea. Tell the camp about vegetarian or other needs in advance.
In more detail
Desert dinners follow the shape of a Moroccan feast. Harira, the tomato and lentil soup, comes first. Then a starter of pastilla or cooked salads, then the main event: a tagine, or mechoui, whole roasted lamb. Almond pastries and mint tea poured from height end the meal. Afterwards the camp's musician often plays by the fire for an hour.
In Agafay, much closer to Marrakech, the range is wider. On our Agafay sunset trip, you take mint tea and Moroccan pastries at sunset and then a three-course Moroccan dinner around the fire with Berber drumming. Some Agafay camps run full restaurants: Agafay Luxury Camp has two, one for international plates and one for seasonal Moroccan cooking, and Le Soukoune is built around private dining tents and a terrace with Atlas views. Kasbah d'If serves breakfast on a patio with desert views.
Alcohol depends on the camp, so ask. It is never included on our trips; Kasbah d'If, for one, has a bar.
Drink the bottled water provided rather than camp water, which is usually drawn from a well or trucked in. Vegetarian and other dietary needs are easily handled if flagged in advance, so tell us when you book.