Step 1: Prepare the vegetables by peeling and dicing the sweet potatoes into 1/2-inch cubes and finely chopping the onion and garlic.
Step 2: Add the sweet potatoes, black beans, diced onion, and garlic into the base of a 6-quart slow cooker.
Step 3: Pour in the crushed tomatoes and vegetable broth, ensuring the vegetables are mostly covered.
Step 4: Sprinkle the chili powder, cumin, smoked paprika, salt, and pepper over the mixture and stir well to combine.
Step 5: Cover and cook on low for 6-8 hours or on high for 3-4 hours, until the sweet potatoes are tender.
Step 6: Stir in the fresh lime juice just before serving, and mash a small portion of the beans if a thicker consistency is desired.
Step 7: Serve hot in bowls, garnished with fresh cilantro and your choice of toppings like avocado or sour cream.