National Italian Beef Day is observed in the United States every May 23. This unofficial food holiday celebrates the Italian beef sandwich, which originated in Chicago, created by Italian immigrants in the early 20th century. The sandwich features thin slices of seasoned roast beef served on a French roll, often topped with sautéed sweet peppers or Chicago-style giardiniera. The beef is typically made from sirloin, top round, or bottom round cuts, slow-roasted in broth with herbs and spices, resulting in tender meat served au jus. The holiday was established by Buona, a family-owned restaurant chain in Chicago, to promote this iconic dish during National Beef Month. To celebrate, people are encouraged to enjoy an Italian beef sandwich and share their experiences on social media.