A Good Day for Some Deep Dish Need an excuse to go out to a new restaurant or to order in? Well, I got you covered. It's National Deep Dish Pizza Day! Pizza is a superfood. Truly great in all forms. We're talking flatbreads, calzones, and of course, the layered deep-dishes. The Chicago-style, deep-dish pizza is said to have been invented at Pizzeria Uno in 1943. The Chicago restaurant's owners, Ike Sewell and Ric Riccardo, are credited with the discovery. However, there is a bit of contention around the topic. Adolpho Malnati Sr, a former employee at Pizzeria Uno, believes it was his idea that created the deep-dish pizza. After a bit of tension between the families, Malnati’s son Lou left Pizzeria Uno to start a different deep-dish pizza establishment in 1971.