Put this on the barbecue about 20 minutes before you begin grilling the main course so that it has enough time to cook through. Keep warm on the warming rack of the barbecue or in the oven.
6 medium potatoes, peeled or not, cut into 1/2-in. chunks
1 1/2 medium onions, sliced
3 tbsp olive oil
1 tbsp chopped rosemary
1 1/2 tsp salt
1/4 tsp black pepper
Preheat the barbecue grill to medium. Cut a double layer of heavy-duty foil wrap, 18 x 24 in (45 x 60 cm). Lightly spray the foil on one side with non-stick vegetable oil baking spray.
In a bowl, toss together the potatoes, onions, olive oil, rosemary, salt and pepper. Spoon onto the middle of the foil rectangle and wrap securely, folding the sides and top with a double fold. Place packet on the preheated barbecue grill and cook, turning the packet over 3 or 4 times, for 25 to 30 minutes or until the potatoes are tender. (Peek inside the packet – watch out for steam! – after about 20 minutes to check on the progress.)
Carefully unfold packet, remove potatoes to a bowl and serve.