It's a solid spicy 'brick' which you add to the hotpot before cooking vegetables and rolled lamb slices as well as sliced potatoes in the hotpot itself. You can also call it malatan. There are various companies that make this kind of product.
Here in a suburban district of Hohhot, I buy the meat at 21 RMB/ half kilo. But near the city centre it costs at least 28 RMB/half kilo.