We made some very simple stuff that came out great in our Dutch oven. Vanilla cake mix, butter, and canned pie filling. Spray out the oven, put the pie filling down in it, then cover it with the cake mix. Dot it with butter. Put it on the fire (on a rack or on logs that are stacked up, not directly down in it). Cook until the crust is golden brown. If you have ice cream to serve with it that would be AMAZING.
Tater tot casserole: Basically just put a layer or two of frozen/cold tater tots in the DO, and then after they are cooked about halfway put a layer of cheese on top. Easy peasy and SO GOOD.