Each top is cast in a highly engineered composite concrete, and sealed with a cutting-edge reactive sealer that cannot peel or yellow. The steel base is crafted in-house, each piece carefully cut and fitted, each weld obsessed over to ensure many lifetimes of use, and when finished, each receives a hand-rubbed wax finish.
I don’t know for sure, but I bet Brandon would sell you one, if you’re interested. Or, you could try making your own by pouring concrete into a melamine mold box (as in this tutorial from DIY Network) with upside-down saucers glued to the bottom. [Thanks, Brandon!]