Though similar ancestors abound, modern xiao long bao emerged from Nanxiang, on the outskirts of Shanghai, and the best possess thin, delicate skins, a meaty pork filling and an abundance of broth.

For Modern Shanghai’s award-winning xiao long bao (it was recently named No. 1 in the local dining scene by spot.ph), it takes a bit of ceremony to enjoy it.

Xiao Modern Asian Bistro is gone. But owners Frank and Michelle Cheng are still there. So is the sushi and the lunch buffet. The Chengs have opened a new restaurant, Cask & Co., in the same ...