I first discovered Yum Bun online and then in person at Broadway Market (http://eatlikeushi.posthaven.com/broadway-market-london-2012-2013). In fact, I made my maiden trek to this market just to try them. As I had visited David Chang's Momofuku a year earlier, I was surprised (and amazed) to find I enjoyed the Yum Bun versions more. Maybe it was the cold weather and rain, but they were so very great.
As the months went on, I visited Broadway several times for the buns, but they seemed to appear there less and less (including on my birthday in 2012 which I was bitterly disappointed). Eventually they opened the store front and it became apparent.
The buns were as good as ever, better than the USA, Melbourne and other parts of London and Europe that were doing them. They are still my favourite and will remain so. Despite a few different flavours, the original pork belly will always be the best. One particular time the pork had a crisp textural shell. I thought it was skin, but the owner told me they never use skin and so it must have been crispened by the grilling. I'll have to remember to ask for that every time.
It's a shame the store has now closed.
01-2018
It's been a long time since Yum Bun graced my lips and in that time it appears Bao has become the premier bun place (even though I haven't tried it). The revamp of the foodie section of Spitalfields gave me a good opportunity to try again my lost lust.
£7.5 for 2 buns or £9 to include the meal (salad) and an extra £1 for a flavoursome soup (not miso but equivalently nice).
Unfortunately the bun quality has deteriorated over the years. Firstly the pork bun no longer comes with hoisin but instead used another sauce (plum sauce I think) which changes the flavour completely and not for the better. The pork is smaller but still reasonable sized but look at those tatty broken peeled buns. Compare with the beauty of the originals from Broadway Schoolyard market or the store near Old St and there is a significant difference.
Tofu was heavily fried and had very slight flavour.
Despite that, it had the longest queues in Spitalfields so maybe not everyone shares my view (or my nostalgia).