Heat a camping stove to medium-high (about 375° to 400°F), or fit a grilling grate over the direct heat of glowing embers.
Melt the butter in a 12-inch cast-iron skillet on the camping stove or grilling grate directly over the heat source. Add the sausage to the skillet, and cook, stirring until the sausage crumbles and starts to brown, about 3 minutes. Push the sausage to one side of the skillet.
Add the gnocchi to the empty side of the skillet, and cook, stirring occasionally until browned, about 1 minute. Stir the tomatoes, stock, and beans into the mixture in the skillet; cover and cook 4 minutes. Sprinkle with the cheese; cook, uncovered, until the liquid is thickened, the gnocchi is tender, and the cheese is melted, 1 to 2 minutes. Sprinkle with the parsley, if desired.