Sorry, most of the Lebanese/Syrian places I have tried in London were casual places. I don’t recall any ‘fine dining’ that comes to mind. However, in the same amount of time as an overnight train (possiby?), how about a flight to Tel Aviv or Lebanon? 
Just returned from Israel and was very pleasantly surprised by all the incredible food options there, from falafal from street vendors washed down with freshly squeezed fruit juices to ‘fine dining’ in whitetable clothed restaurants with very good delicious Israeli wines…
