Classic dishes in a tagine use pieced meat...stews, chicken parts, flat roasts (brisket should work, but not a rib roast). As josh noted, the point is to have the savory liquid circulating all around the food.
My favorite is chili. Also working up some beef stews. Sure, the North African seasoning blends are the classic, associated ones, but they're by no means the only ones to consider.
More or less in order of addition to the pan: