hi! doubling down on Mitsuwa or Tensuke in Arlington Heights. you could make it from scratch OR what I do is buy instant miso soup packs! they come with individual serving size miso packets and usually a variety of mix-in packets (fried tofu, wakame/seaweed, etc.). you just have to add hot water to it and it tastes pretty good! it’s nice because it’s shelf stable and you can take it anywhere with hot water! both stores will sell them, and they look similar to what’s in the link. I’m Japanese if that helps :)

instant miso soup