Method
The first thing to do is light your barbecue. As a general rule, it’s a good idea to light a charcoal barbecue 30 minutes before you want to start cooking, so that the charcoal has time to reach the right temperature; the barbecue is ready for cooking when the coals are coated in white or grey ash. If you are using wooden skewers, put them to soak in some water when you light the barbecue, so that they won’t catch alight on the grill. When your charcoal is up to temperature, melt the butter in a saucepan over a medium heat (you can try doing this over the grill – carefully - if you want to, but a hob is probably easiest). Add the chopped onion and garlic, and cook for about five minutes until soft and translucent. Remove the pan from the heat, and stir in the lemon juice and salt. Place the scallops in a shallow dish and pour the butter mixture over them, turning them with a spoon to ensure an even coating. Let them sit in the butter for a couple of minutes, then thread them on to the skewers and cook on the grill for about 3 minutes per side. Serve sprinkled with the chopped parsley.