You can buy a same-day return ticket for the same price as one-way. I'm not sure that going to a restaurant would be high on my list for such a stopover (you have lots of food onboard both flights, plus the lounge has both hot and cold food on the J side, and better food than most restaurants on the F side). The best view is on the Kowloon side, an alternative is to have a drink at Felix, a bar at the top of the Peninsula hotel (it is world famous thanks to a Starck design and some interesting features). You can get there on the Star Ferry. Just leave plenty of time to get back to the airport and spend some time shopping there.