Cooking in a pot works well enough. If you'd rather make three dishes in one fell swoop instead of one, though, this Steam Stacker should make for a useful kitchen equipment.
Designed by Christian Bjorn for MENU, the multi-piece cooking tower is based off those bamboo baskets that the Chinese folks use to make dimsum. Instead of steaming food over a simmering pot of water at the bottom, though, this set is designed for oven cooking with the bottom layer acting as both the source of steam and a collection pot for all the flavorful juices whatever you have sitting on the upper layers sweat out.
The Steam Stacker is a five-piece cooking tower consisting of three food bowls (two with holes) and two lids. One lid goes on top to keep the steam in, with the other serving as a pinch-hitter, in case you break the other one. The two lids can also be used as a serving base for the two holed bowls, so their drippings don't mess up your table.
While designed for oven cooking, this will probably work for cooking over fire, too (provided you really just want to steam the grub on the upper two layers). The idea is that the vapor from the bottom bowl (say, you've got potato soup on there) will steam the other two dishes you've got on top of it, with juices from the meat on top and the veggies in the middle trickling down to season your ertswhile bland carbs on the bottom in a delicious-sounding commingling of flavors.
Amazon has the MENU Steam Stacker, priced at $99.