Sausage and White Bean Soup

2 tablespoons olive oil
1 1/2 pounds Italian sausage, in casing
2 medium carrots
2 medium onions
2 stalks celery
1 teaspoon thyme leaves
3 (15 ounce) cans white beans
1 quart chicken broth
1 teaspoon dried thyme

Heat oil in large, deep pan. Brown whole sausages; remove to cool for about 5 minutes. Cut celery, onions, and carrots into small dice. Brown vegetables in same pan for about 10 minutes. Puree one can of white beans; add to vegetables. Cut sausage into small slices and add to vegetables, along with broth and remaining beans. Simmer 20 minutes.