If you love BBQ pork buns, I would try this recipe out. It has a different flavour profile than a BBQ pork bun, the filling is much less sweet, but just as delicious. You could probably even substitute in some BBQ pork from your local Chinese grocery store for the filling if you wanted to as well.
It was fun to try Union 613 for brunch and I really liked that when they could possibly make something in house, they did. Even the little things, like the ketchup for example, which is probably easier to just buy, they took the time to make from scratch.