The Middlesex Diner in Carlisle, Pennsylvania, is precisely that kind of place – a no-frills establishment where locals line up for what many swear is the best French onion soup in the Keystone State.

Gołąbki (pronounced go-WOHMP-kee), as they’re traditionally called, might not have the most appetizing English name – “cabbage rolls” sounds utilitarian at best – but these are no ordinary cabbage ...