Panera Bread Black Bean Soup

1 onion, finely chopped
2 cloves garlic, minced
2 celery ribs, finely chopped
1/4 large red or green bell pepper, finely chopped
2 small chicken bouillon cubes
1-1 1/2 cup boiling water
2 cans black beans, undrained
1/2 teaspoon salt
1/2 teaspoon cumin
1/2 lemon, juice of
1 1/2 tablespoons cornstarch

1. In a pot, combine the first six ingredients; simmer for 10 minutes.
2. Add half a can of beans, salt and cumin; cook for 5 minutes.
3. Puree soup (I use an immersion blender which makes it easy to do it right in the pot).
4. Add the rest of the beans to the soup.
5. Combine the cornstarch with 1 1/2 tablespoons of water.
6. Add the lemon and the cornstarch to the soup; cook until thickened.