Maxwell Street Polish is a type of sandwich that's named after a street in Chicago. The sandwich is made with Polish sausage, which is a type of sausage that's popular in Poland. The sausage is put on a bun and then topped with grilled onions, yellow mustard and sometimes hot peppers.
It's kind of like a hot dog, but it's made with a different kind of sausage and it has different toppings. People in Chicago really love Maxwell Street Polish sandwiches and they're a really popular food there.
Some people say that the sandwich was first made by Polish immigrants who worked on Maxwell Street in the early 1900s. They would grill sausages and sell them on the street, and eventually people started putting them on buns and adding toppings.
Nowadays you can find Maxwell Street Polish sandwiches at restaurants and food stands all over Chicago. They're really tasty and they have a lot of history behind them!