Mentioned by NerdWallet
Cheap Eats Chicago: 5 Under $5
"Known for its Chicago-style hot dogs and Italian beef sandwiches, Portillo’s has been a staple of Chicago since 1963. Most of the hot dogs, sandwiches, burgers and sides on the menu cost $5 or less. Besides Chicagoland, Portillo’s also has locations in Arizona, California and Indiana."