1. In a large pot, with oil on medium high heat, sauté onion, celery and carrots for 3 minutes.
2. Add sweet potatoes and sauté for 3 minutes.
3. Add Roasted Chicken Base and water, stirring until base dissolves. Bring to a boil. Let simmer for 10 minutes or until sweet potatoes are soft.
4. Add chicken, kale and black pepper. Let simmer for 5 minutes.