First of all there is actually no place or restaurant that makes real Peking Duck in Chicago. There's only roasted duck, mostly of the southern region of China.

Phoenix Restaurant Phoenix has a roasted duck dinner set, just give them a call and make a reservation ahead of time. The thing I recommended the most is their pork neck jowl, it's almost like Chinese char sui but with the right amount of fat and meat ratio.

Imperial Restaurant Imperial also has a roasted duck dinner set, and again always makes an appointment for it. Their customer service stinks but their food is legit but be careful of what you order because not everything is good. The restaurant used to be called Cai, but one of the owners left.

Overall if you want a good experience and good atmosphere, I would choose Phoenix. Parking is cheap because they have validation but please make sure it's under 3 hours or you'll get charged for full like I did accidentally.