Step 1: Prepare your ingredients. Dice the chicken thighs into 1-inch pieces. Peel (optional) and dice the sweet potatoes into 1/2-inch to 3/4-inch cubes. Mince the onion and garlic. Drain and rinse your canned black beans and diced tomatoes.
Step 2: In your slow cooker, combine the diced chicken, sweet potatoes, diced onion, and minced garlic. Evenly distribute them at the bottom.
Step 3: Add the canned black beans (drained and rinsed), diced tomatoes (undrained), tomato paste, and chicken broth to the slow cooker. Stir gently to combine these wet ingredients with the solids.
Step 4: Sprinkle in all the spices: chili powder, ground cumin, smoked paprika, dried oregano, and cayenne pepper (if using). Add salt and black pepper to taste. Stir everything together until the spices are well distributed and all ingredients are combined.
Step 5: Cover your slow cooker and cook on LOW for 6-8 hours or on HIGH for 3-4 hours. The chili is ready when the chicken is cooked through and easily shredded, and the sweet potatoes are tender.
Step 6: Once cooked, remove the chicken pieces from the slow cooker and shred them using two forks. Return the shredded chicken to the slow cooker and stir it back into the chili.
Step 7: Taste and adjust seasonings as needed. You might want a pinch more salt, a dash of hot sauce, or a squeeze of lime juice to brighten the flavors. Serve hot with your favorite toppings like fresh cilantro, shredded cheese, sour cream, or diced avocado.