It is especially praised and heavily consumed in Hong Kong, where shops and food carts serve it anytime and everywhere, either as a finger food or a complete meal, but always ready to go.
The shops serving it are siu laap shops or Cantonese charcuteries. Don’t think of fancy ‘western’ charcuteries, but more like places where the storefront is small and packed with meat cuts and the back where the roasting oven and kitchen is.
Here’s a video on how do they sell to the long queue of customers:
As you can see, ordering siu laap is very special: you need to know about the pieces, sizes, weighting, and some sort of mute language (instead of yelling your order), and you can learn to do so in here.