SCMP article (attached below) said the much-loved signature dish Sutadon (rice/pork/garlic) from Sutadonya in Japan is here for a short time only. Something special? I don't know, they were using whey-fed pork from Northern Italy I guess, but either way was good excuse to go to Mong Kok at lunchtime to check it out.
Dondonya Shokudo is a six-outlet chain of casual Japanese restaurants in HK. Not sure of the commercial arrangements with Sutadonya but chef has shown all six outlets in HK how to make his dish and they're headlining with it for few months.
Was light, tasty and not overloaded with garlic. My onsen egg was little overcooked (not entirely runny yolk) but my lunch buddy's was perfect. Pork was shaved thinly and pickled daikon radish was nice (though unimaginative) accompaniment.
Not sure I'd travel too far out of my way for this, but it was nice and if the back story gets you excited and you're near one of their outlets then give it a try. Only HK$58 for meal and bottled Asahi just HK$22 -- bargain!