Heat olive oil in a large pot and cook the onion, carrot and capsicum until softened.
Add chilli and garlic and cook for 1 minute
Add sweet potato, cumin and smoked paprika and stir to coat.
Stir through tomato paste and cook for another minute.
Add tomatoes and stock and bring to a simmer
Cook for 25-30 minutes until the sweet potato is very tender.
Add black beans and corn and simmer for another 10 minutes.
Lightly mash some of the sweet potato against the side of the pot to thicken the soup naturally.
Stir through lime juice and season generously with salt and pepper.