Black Bean Soup

This is a new favorite soup recipe of mine. I first tried it last year at Panera Bread and loved it so I did a google search to find something similar. Here it is:

4-6 servings
25 min, 5 min prep

1 onion finely chopped
2 garlic gloves minced
2 celery ribs, finely chopped
1/4 large red bell pepper, finely chopped
2 small chicken bouillon cubes
1-1 1/2 cup boiling water
2 (15 oz) cans black beans, undrained
1/2 teaspoon salt
1/2 teaspoon cumin
1/2 lemon, juice of ( I was unclear as to what this was, I think I did 1/2 Tablespoon?)
1 1/2 tablespoons cornstarch

1. In a pot, combine the first six ingredients; simmer for 10 min.
2. Add half a can of black beans, salt and cumin; cook for 5 minutes
3. Puree soup. (I used my blender)
4. Add the rest of the beans to the soup
4. Combine the cornstarch with 1 1/2 tablespoons of water.
6. Add the lemon and the cornstarch to the soup; cook until thickened