If your barbecue hasn’t already been heated, light and heat until the ashes turn grey. Put the potatoes in a large saucepan of cold water and bring to the boil. Once boiling, cook for 5 mins until slightly tender.
Drain and leave to steam-dry for 2 mins. Transfer to a large sheet of foil, coat in the olive oil and season well. Make sure the potatoes are sitting flat against the foil so each one gets charred when grilled. Wrap in the foil like a parcel, and wrap again to ensure the potatoes are completely covered. Cook on the barbecue for 10 mins.
Check they are cooked by inserting a skewer into one of the potatoes. Carefully remove from the foil and serve in a dish.
To cook in the oven
You could also bake these baby potatoes in the oven. They won’t have the charred flavour they get when you barbecue them, but if you cook them on a baking tray without covering in foil, you’ll get lovely crisp skins.