Instructions

1. Peel the sweet potatoes and carrots, then cut into chunks.
2. Put them into a saucepan, cover with water. Add the garlic and cook until the vegetables are soft.
3. Drain then put back into the pan. Add half of the vegetable stock and oil. Blitz with a hand-held blender until smooth. Add more stock & oil if it's too thick.
4. Add the herb (if used) and blend for a few more seconds.
5. Serve warm.