In fact, all the supermarkets in Beijing sell some local specialties, but they are not complete.

packaged and storable snack foods such as chafing dish base, Hechuan peach slices, Zhang Fei beef, strange-flavored beans and Chongqing twist are relatively easy to find.

However, it's hard to find it in major supermarkets. I suggest you buy it directly on major shopping websites. These local specialties are relatively complete online. It is also much more convenient!