Heat the barbecue to hot.
It is really important to look after your asparagus; handle it gently or you will bruise it. Start by trimming the spikes off the spears back up to the head. Cut all the spears to one even length.
Blanch the asparagus for about 1½ minutes in a saucepan of salted boiling water. Remove and refresh in iced water until cool.
Rub the spears with oliv