White bean soup with crawfish sausage and mustard greens

It's essentially a variation on white bean, sausage and spinach soup, but I really like the tang of the mustard greens. It offsets the creaminess of the beans very nicely. Of course you can use regular sausage, I used the last of the crawfish sausage from Louisiana (which, incidentally, also went very nicely with the mustard greens).

I was on a beans kick there for a while, but I think I'm over it.

The equivalent of four cans of white beans
1 onion, chopped
2 carrots, chopped
2 celery stalks, chopped
1 lb sausage, sliced
Broth
6-7 leaves of mustard greens, sliced

Saute the onion, carrots and celery in olive oil or bacon fat until soft. Add the sausage and cook until it's a little browned. (Here, you can deglaze with a little white wine, if you have any.) Add enough broth to float everything, and let cook on medium-low for 30 minutes or so. Add the mustard greens and cook for another 2-3 minutes. Salt and pepper to taste.