Eons ago, back in my college days, I was part of a crew of six friends from tjhe University Geology Dept and outing club. We took a trip to the Carlsbad area of NM to do some research sponsored by the US Park Service in many of the caves of the region. We dorve there from NY over Christmas break and spent several days in one, Cottonwood Cave, which has a huge 300x200 ft gaping entrance, sloping down to a flat silty lower level as part of the main entrance before opening up to miles of multiple passages to explore. It was big enough and safe enough to camp right there, well within the entrance. This is where we slept and prepared our meals using a two burner Coleman stove. Meals tended to be one pot throw together whatever we had. Since it was winter and rather chilly in that entrance area, there was no need to exit the cave or to waste water to clean any utensils or pots. One meal's leftovers blended into the next in the single pot. Yum.