Julia X.
Yelp
Ah, my beloved Joong Boo, my favorite Korean grocery store in the city. Love that it is nearish to a blue line stop (Belmont, the one near Logan Square), and that it has the Snack Corner food court.
They also carry tons of items like fresh produce and face masks and whatnot, so you really can't go wrong. My favorite grocery items to buy here: organic mushrooms (they have so many kinds!), tofu, sashimi, East Asian sauces, dried seaweed, various greens, fresh tteok (seems like they get theirs from Nakwon Tteok House).
I will say that sometimes they randomly stop carrying brands (rip that miso with the little boy on it that I liked) and the aisles are very small, so try to avoid peak times.
The Snack corner (hours: 10am-7pm) is also basically a must-visit every time because they have a lot of korean food options at super reasonable prices. The portions are also generous. My favorites: nakji bokkeum (no. 20), soon doobu (no. 4), kimari. The mandu shop right outside also has amazing, giant, fluffy red bean buns. The snack corner only has 5 tables, so definitely try to come at an off time (though I have yet to find out exactly when that is lol - probably right at 10 or weird afternoon times, or right near closing). Sometimes they run out of napkins, too, so be prepared. If you are a big group I would also recommend ordering all together at once since they seem pretty short staffed so the person taking orders sometimes leaves after taking one, with a big gap in between. Sure, the ambiance isn't great and I would say the food is solid but not amazing (definitely found the beef in some dishes to be dry and old), but for those prices and those portions it's pretty dang good.