Given you are based in SF, I am quite surprised you are not familiar with dum sum and Hong Kong milk tea.

Dim sum in a general term, it is not leaf wrapped dum sum. It is usually chicken with rice wrapped in lotus leaf. (in your case vegetable instead of chicken) The correct term in cantonese is Chan-Chu-Chicken.

Hong Kong milk tea is a british thing (if you don't know Hong Kong is a British colony up until 1997) However, I can really doubt they can make it from scratch on the plane, probably using those 3-in-1 milk tea packets from Lipton. (though I had never asked any CX FA about it !) Next time while you are back home, I suggest you go to one Hong Kong base restaurant and try a real one to compare.