It seems Zah Jiang Mian is originally from China. Then it was arranged in each country or region.
In Japan, Morioka ( the capital city of Iwate prefecture ) is known for it. In Morioka, they use think white noodle ( udon ). They use freshly grated garlic as condiments (if you don't have any date, fine go ahead ! )
This one was pre-packaged and the noodle was regular yellow ( ramen noodle).
Boil the water and cook the noodle for 2 min. and then wash it with cold water. The sauce is also in the package, so pour the sauce. ( It has sweet and spicy miso, ground pork meat and spices... yummy sauce ! ). Add thinly sliced cucumber and edamame ( or any veggie you like, but cucumber works good ! ) . I added spicy oil. Next time , I should try to cook this special miso ! I wanna try Morioka version someday.
There should be a history since Morioka has other arranged noodles such as Reimen ( originally from Korea) and Wanko soba noodle.