WE tasted life as a first class passenger on Qantas yesterday - and we didn't even leave the ground. It was all to do with Australia's national airline deciding to blend, as a spokesman put it, ''Qantas and the Regent, two of the institutions in the Asia-Pacific region''. So for the next few months, pampered first class passengers on board the airline will be eating dishes prepared by the chefs of the various Regent hotels in the region. At lunch yesterday, the Regent's Hong Kong executive chef Jurg Blaser served up white asparagus marinated in truffle vinaigrette followed by sauteed beef tender loin with pak choy ravioli, two delectable dishes that will be served on Qantas flights out of Hong Kong. But Regent GM Thomas Axmacher, who hosted the lunch at the Plume, was not leaving anything to chance. He commented: ''I will, of course, have to take a few Qantas flights just to ensure that the food tastes as superb up at 35,000 feet as it does in my restaurant''.