Ever wondered what is on a Big Mac®? The McDonald's Big Mac® is a 100% beef burger with a taste like no other. The mouthwatering perfection starts with two 100% pure all beef patties and Big Mac® sauce sandwiched between a sesame seed bun. It is topped off with pickles, crisp shredded lettuce, finely chopped onion, and a slice of cheddar cheese. It contains no artificial flavours, preservatives, or added colours from artificial sources.