Salt is a newish restaurant in the New Maru Biru at Tokyo station. It's Australian food with a few Japanese twists. I don't usually like "fusion" cuisine, but this was more understated - I had the risotto with nori, and it was really nice. Subtle. In addition to fish and meat, there's a reasonable vegetable menu that gave me lots to choose from. Portions are generous, and though it's a white tablecloth place with attentive service and an elite atmosphere, prices are not that high - most main courses are ¥2-3000.
There are lots of nice places to sit around in this schmancy building, which I like better than both Roppongi Hills and Tokyo Midtown, as far as upscale malls go. There are lots of swanky restaurants and good views of pretty brick Tokyo Station.