I finally got to go to Wasabi Bistro to try their 4-hour Sunday brunch (I think buffet also available for Sat lunch but shorter hours). They serve Hawaiian/Californian influenced Japanese. All beautifully presented. Their signature dishes made me feel like royalty! The rest of the menu not that great though (with the exception of a yummy teriyaki beef tenderloin and nice tangy seaweed salad). The a la carte buffet is quite pricey at S$58 but you can easily eat more than your dollar's worth. Add S$55 for free-flow champagne, sake, beer and other booze.

Service is impeccable, stemming from the Mandarin Oriental's tradition.

Full review too long to post here (over 20 photos!) so see links below for details.

Part I - the signature dishes

Part II - the other dishes on the menu