I found this recipe at http://www.aboutamom.com.  The carb count is not available but based on the ingredients, it is very low.

INGREDIENTS:

• 3 boneless, skinless chicken breasts
• 32 oz. chicken stock
• 1 (14.5 oz.) can diced tomatoes
• 1 medium yellow pepper, diced
• 1 medium red pepper, diced
• 1 medium onion, diced
• 2 cloves garlic, minced
• 6 oz. mushrooms, thinly sliced
• 1 (8 oz.) package McCormick Taco with Chipotle & Garlic Skillet Sauce (I could not locate this sauce so I used 6 oz. tomato paste, paprika and chipotle chili powder)
• 1 tbs. season salt
• 2 tbs. fresh cilantro, chopped

INSTRUCTIONS:

1. Except for the fresh cilantro, add all ingredients to the slow cooker.  Cover and cook on low for 6 hours.
2. Using two forks, shred the chicken breasts.  Gently stir in fresh cilantro, cover, and continue cooking for an additional hour.

This recipe makes a lot of soup, about 14 cups.  I topped off with a little sour cream.