Bring 3 quarts of water to a simmer in a large soup pot over high heat. Add the bouillon cubes. Reduce the heat to keep the liquid at a simmer and add your choice of the longer-cooking ingredients. Let them simmer away until everything becomes fairly tender, about 30 minutes.
Add your choice of the shorter-cooking ingredients, season with salt and pepper to taste, and let the soup simmer for another 15 to 20 minutes or so. Start tasting the soup toward the end, and when the flavors seem to be blended and the consistency of the ingredients is as you like it, serve it up -- it's soup! Sprinkle some cheese on top, if you like.