Want to cook up a circular egg that will fit a bagel or english muffin perfectly? You could always use your standard egg rings, but mason
jar rings work just as well. According to The H Blog, a standard 10-ounce wide-mouth pressed steel mason jar ring will hold a large egg perfectly:
Just spray the ring with your cooking spray of choice. Place the ring in your skillet and crack an egg inside. Cook on medium low heat for a minute or two and then remove the ring; the egg will stay in the circular shape. Flip the egg over and cook for another minute and it'll be ready to eat.