As its name suggests, Diana's Food & Restaurant is half convenience store and half restaurant in the heart of Humboldt Park. While the restaurant does randomly serve some tacos and burritos, it's the authentic Puerto Rican dishes that really shine.
Most of the sandwiches they serve are pretty delectable, but my favorite is the bistec sandwich. It arrives warm on a pressed roll and features a generous portion of sliced steak, which is beautifully beefy, moist, and tender. The fear I have with most steak sandwiches is that you end up fighting with the meat, but not in this case. The bread, too, was great—warm and crunchy, and I didn't end up with any damage to the roof of my mouth. All their sandwiches come with lettuce, tomato, mayo, and cheese, and the vegetables did add a spot of crunch and brightness to the otherwise filling sandwich.
Diana's is steps away from Humboldt Park, so my advice is to grab a sandwich, a couple of their Frituras, and a flan and go enjoy it as you sit on some grass under a shady tree.
Diana's Food & Restaurant
1000 North Francisco Avenue, Chicago, IL 60622 (map)