I go here quite often after work for a quick dinner or for lunch with coworkers. I am from Chicago and this is as close to a Portillo's as you're going to get. Joey's of Chicago doesn't compare to Luke's of Chicago. I highly recommend.
They have homemade giardiniera hot peppers and quality beef. I normally get the Italian Beef sandwich with the giardiniera hot peppers. You can also buy a jar of the hot peppers for a reasonable price. If you're looking for a quick, high quality beef sandwich in the valley, you'll find it at Luke's of Chicago.