But what exactly is a bao? The word simply means “bun” (so “bao bun” is tautologous) and it can cover several shapes, although most fall into one of two categories. First there are the stuffed buns, a mainland Chinese tradition, neat round dumplings with a small amount of filling completely enclosed in steamed salt-sweet bread. They often have a coloured dot on the top to identify the flavour – Itsu has taken this route with its bao. 

Then there is the simple folded bao, a flat semi-circular or oval bread folded to make something that looks like a Muppet but does the job of a mini burger bun, ready to be stuffed with a spicy, savoury, punchy tasting filling – traditionally pork belly. Popular in Taiwan, they are sometimes called a gua bao and were made trendy by trailblazing London restaurant Bao, which started selling them on a street food stall in 2012. M&S, Waitrose and Asda all sell them empty for you to supply your own filling, and this is the route to go if you want to avoid the kind of industrial ingredients that mark food out as ultra processed: all the stuffed buns from the supermarkets had some additives.

If you do want stuffed bao, but with lower levels of dodgy ingredients, reach for Japan Menyu katsu bao from Waitrose and the Imperial Chicken Teriyaki Bao Buns from Morrisons. Sadly, the great-tasting Akira range from Asda was among the worst for weird additives. The best-looking ingredients list doesn’t always go hand in hand with the best flavour. 

As for those unstuffed bao breads, Cen declared Asda the clear winner. “They are almost homemade looking, with a smoother texture and really good seasoning, a balance of salt and sweet. Mind you, that’s partly my taste,” he added, “My family is from the south of China where the buns are sweeter, while in the north they are saltier.”