Deep-dish pizza was invented during the '40s in a lumber baron's former mansion at 29 E. Ohio St. — now the site of Pizzeria Uno. But the inventor is unclear, with credit going variously to restaurant co-owners Richard Novaretti (a.k.a. Ric Riccardo) and Ike Sewell and their employee, Rudy Malnati Sr. The invention of deep-dish pizza might not have happened if not for a twist of fate. At first, Sewell wanted to open a Mexican restaurant. But a test meal went wrong, sickening Riccardo. He suggested they try Italian instead.
Nancy Stone, Chicago Tribune