McMuffin is a family of breakfast sandwiches sold by the international fast food restaurant chain McDonald's.

The round shape of the egg is made by cooking it in a white plastic ring surrounded by an outer metal structure.

[7] Former McDonald's President Ray Kroc wrote that Herb Peterson and his assistant, Donald Greadel, the operator of a McDonald's Santa Barbara franchise in Goleta, California,[8] asked Kroc to look at something, without giving details because it was: ... a crazy idea — a breakfast sandwich.

The advent of the Egg McMuffin opened up a whole new area of potential business for McDonald's, the breakfast trade.

[5][3]One reason the sandwich was served open-faced was that a small tub of strawberry preserves was provided, along with a knife.