More precisely at the Uno pizzeria in Chicago.
This pizza was very popular during World War II because it could feed a lot people and it was not costing much to make it.
Chicago-style pizza has a buttery and heavy crust that could be up to 3'' tall (at the edges), a bit more of cheese than regular pizzas and A LOT chunky tomato sauce. The dough basically acts as a bowl.
Ingredients: usually the oil used for the dough, is olive oil. In the traditional version, mozzarella cheese is used. Then, generally, ham or Italian sausage with mushrooms and onions are added. All is topped with heavy chunky tomato purée.
From Wikipedia's article about Chicago-style pizza.
