Wash the potatoes and halve or quarter any large potatoes. Separate the leaves of the shallots. Place the potatoes, olive oil, rosemary and seasoning in a bowl, mix thoroughly and then arrange in the half-moon (perforated side).
Place the potatoes in the preheated barbecue and cook for 20 to 25 minutes at 180° C until golden-brown. Remove the potatoes from the barbecue, leave to cool slightly and then arrange on the wooden skewers with the shallot leaves. Grill the potato-shallot skewers in the preheated barbecue for around 5 minutes on the indirect setting at 180° C.
Place the skewers in water around half an hour before use.
5 minutes at a medium setting with the lid closed