1Heat oil in a large saucepan over medium-high heat. Add onion and garlic. Cook, stirring for 2 - 3 minutes or until onion has softened (please note: do not brown the onion).
2Add tomatoes, potato and salt. Add tomato paste, then cook for 1 minute.
3Add stock and season with pepper. Cover and bring to the boil. Reduce heat to medium-low, then simmer for 20 minutes OR until sweet potato is tender. Set aside for 5 minutes and allow to cool (slightly).
4Add fresh basil. Blend in batches until smooth, then serve.