CHICAGO STYLE This is the King of the deep dish pizza, in terms of sizes, weight and popularity. The pizza is baked in an oiled pan, quite deep. This kind of bulky pizza is more similar to a pie than a flatbread, but even if it is very thick, the crust itself is thin to medium in thickness. The majority of the volume of the pie is due to the huge amount of cheese and sauce and all the other toppings layered on top.
this is a Chicago style pizza pan
The dough is made from wheat flour, but I’ve read some recipes that has semolina flour; this is kind of interesting to me and it’s something that makes me think about south of Italy… I’m pretty sure that Chicago deep dish pizza style has something to do with Puglia or Sicilian cooking culture. Corn oil and butter are usually part of the the recipe, giving it that buttery taste and biscuit texture. Chicago style deep dish pizza is baked in a round steel pan (see the photo above) that resembles a cake or pie pan. The stretching technique is similar to the way you stretch a crostata dough in a trail: the dough is pressed up onto the sides of the pan.
CHICAGO DEEP DISH vs CHICAGO THIN CRUST This controversy is exactly the same at what happen in Rome (Teglia Romana vs Pizza Romana): even in Chicago coexist 2 completely opposite pizza style. It looks like that the Chicago thin crust has been around much longer than the deep dish: cracker-thin crust, square cut, also known as tavern-style; the dough is rolled and not tossed, cooked for long time enough to ensure an extremely crunchy bite, for this reason it cannot be folded (it would brake apart). The pizza isn’t cut in triangle slices, the true Chicago cut for the thin crust is “tavern-cut” into various sized squares, for sharing while drinking a cheap beer. Many Chicagoans believe that this is the real city’s pizza signature. 
Lovemypizza: Best pizza Vancouver. Pizza chef of the year 2019 Canada champion Giuseppe Cortinovis