In the fall, my husband and I have this soup every Tuesday (when we watch House). It is a very easy and tasty soup. I can even handle cooking it after a long day of teaching and grad school. The serving size is for our big appetites, so take it with a grain of salt. Any kind of pre-cooked sausage works- smoked, kielbasa, or (our favorite) buffalo summer sausage. When I can't find arugula, I use kale or mustard greens.