Slice the potatoes to the thickness of
your little finger, discarding the rounded
end pieces. Tip into a pan of cold salted
water and bring to the boil. Simmer for
3 mins until just cooked, then drain.
This can be done a day ahead.
Rub each slice with a little oil and
barbecue until golden and charred on
each side. Place in a dish and sprinkle
with rosemary and garlic, if using.
Drizzle with a little more olive oil,
season with salt and serve.