Sauté Aromatics: Place a large Dutch oven or soup pot coated with cooking spray (or a tablespoon of oil) over medium-high heat until hot. Add the sweet potato, onion, bell pepper, garlic, and jalapeño (plus optional carrots and celery, if using). Sauté for 5 minutes, stirring occasionally until vegetables soften slightly.
Add Base Ingredients: Stir in the chopped cooked chicken, salsa, cumin, salt, black pepper, chicken broth/stock, uncooked rice, and black beans.
Simmer and Cook Rice: Bring the mixture to a boil. Immediately reduce the heat to low, cover the pot, and simmer for 15-20 minutes, or until the rice is tender and the sweet potatoes are soft.
Thicken: Remove the pot from the heat. Add the peanut butter, stirring vigorously with a whisk until it is completely dissolved and the soup is smooth and creamy.
Finish: Return the pot to the stove and cook for 2 minutes more on low heat, stirring constantly (do not let it boil). Taste and adjust seasonings (salt/pepper) as needed. Serve hot.