Heat the oil and fry the onion for 5 minutes until softened. Add the garlic and chilli and fry
for a further 2 minutes. In the same pan, add 300ml / 1/2 pint of the vegetable stock. Bring to the
boil and simmer for 10 minutes.
Mix the cumin with a little stock to form a paste and then stir into the soup. Add the diced
sweet potato, stir and simmer for 10 minutes. Season and stir again. Add the pepper, corn and
remaining stock and simmer for 10 minutes. Process half of the soup until smooth and then stir into
the chunky soup. Season and serve with lime wedges for squeezing over.