Basil Stag's Hare Pawspring Vegetable Soup

1 tablespoon unsalted butter
3 medium carrots, peeled and sliced
2 medium onions, peeled and chopped
2 celery stalks, chopped
1/4 cup tomato paste
1 quart vegetable broth
salt and pepper to taste
2 cups (4 oz) shredded green cabbage
1/2 cup (2 oz) sliced green beans
1 teaspoon cornstarch
crusty bread for serving

Melt butter in a large saucepan over medium heat.  Add carrots, onions, celery
and cook, stirring, for 4 minutes.  Do not let the vegetables brown.

Stir in tomato paste and broth and season with salt and pepper.  The original 
recipe called for vegetable bullion cubes and water.  I just used a carton of 
broth.  I didn't have vegetable broth to hand, so I used chicken broth.  Bring 
to a boil, stirring, then cover pan, reduce heat, and simmer for 10 minutes. 

Stir in cabbage and green beans, cover again, simmer until all vegetables are
tender, another 10 minutes or so. 

In a bowl, blend the cornstarch with a little warm water and stir it into the
soup.  Bring the soup back to a boil, stirring continuously and cook for 2
minutes.  Reduce heat and simmer uncovered for 10 more minutes.  Add salt and
pepper as needed and serve with crusty bread.

I'd be willing to make a double batch of this for a potluck and use vegetable 
broth so the vegans would be able to have it.