1. Heat the olive oil in a 3 litre pot and sauté the garlic and onion.
  2. Add the sweet potato and tomatoes, and stir well until completely covered in the onion and garlic.
  3. Cover with stock and allow to simmer for 1 hour. Remove from the stove and set aside for 10 minutes.
  4. Blend soup using a stick mixer until a smooth consistency has been reached.
  5. Stir through mint and top with sour cream or parmesan.