I had lunch today at Carnitas Uruapan, 18th just west of Paulina... just one menu item, but done really well: carnitas tacos ($1.50 each). Three make a filling lunch. Especially awesome washed down with Jarritos Limon soda.
So, this visit got me thinking about similar places in Chicago. Just one item, but done to perfection. Any other single-specialty places in Chicago I should try? I'm excluding hot dog and Italian-beef joints; that's a thread in itself, or two, or twenty.