Thick sliced bologna best if from deli, However a couple or three thick slices out of packaged bologna works well . Be sure to make two or three cuts toward the center of the bologna to keep it from bubbling up in the center. OR use a bacon press to keep it flat and fry evenly.

Sautee your onions in a gob of butter, frying to the consistency you preferer. I like my onions browned you know caramelized.

Fry egg over hard, salt and pepper

One slice of cheese of your preference. I usually use Kraft American cheese

Mayo of your choice, Miracle Whip or Dukes

put all this between two slices of white bread.