Scrub and peel 3 – 4 sweet potatoes and cut into even-sized chunks. Place in a saucepan and cover with boiling water. Bring to the boil, then reduce the heat and simmer for approximately 15 minutes, until tender.
Drain the potatoes and place in a blender. Add the basil leaves and puree to the desired consistency, adding a little olive oil to thin if necessary.
Delicious mashed rather than pureed, especially as a topping for cottage pie.