Chicago-style pizza, or Chicago-style deep-dish pizza, contains a crust which is formed up the sides of a deep-dish pan. It reverses the order of some ingredients, using crust, cheese, filling, then sauce on top. Some versions (usually referred to as stuffed) have two layers of crust with the sauce on top. The invention of deep-dish pizza occurred in America and transcends a single ethnic origin. Deep-dish pizza was invented by Ike Sewell and Ric Riccardo and first served in 1943 at Pizzeria Uno, which is still operating along with its twin restaurant, Pizzeria Due, in the River North neighborhood.