So, in a sense of fairness and full disclosure, I start by noting that I am a son of the Jersey Shore. 'round here, folks eat pork roll, egg & cheese sandwiches on hard rolls as a matter of pride. Hell, back in the day, a hard roll filled with a slab of butter was also a properly appropriate breakfast - every diner and convenience store offered 'em.
Now, keep in mind we are a short "crow fly" from the Island of Manhattan where fine bagels can make the morning meal. Places nearby make some solid boiled-baked goodness. Consequently, I do like me some stuff - lox, cream cheese, chicken salad - put on one of them "holey" products as my first meal of the day. A good bagel can be quite moving.
I went to college in central Pennsylvania and discovered scrapple. Man, that's fine stuff when coupled with some cheese on one o' them Philly hoagie rolls.* My wife is originally from Northern North Carolina, so, over time, her family has turned me on to sausage and biscuits. Tasty. tasty, tasty - especially with that gravy. Once upon a time, while goofin' off in Virginia, I discovered country ham and biscuits for breakfast - Hell, that's as*-kickin' good.
So I pose the following question: What is your "ultimate" "breakfast on a bun"? I mean, the Egg McMuffin has been famous for decades, right? A day started with a handheld meal is a thing of beauty. Everyone must have an idea.
For what it's worth, I spose I'd have to pick pork roll, bacon, egg, and American cheese on a hard roll. It, however, to be "just right" needs to be wrapped in foil for the five minutes it takes me to get to the beach and eat There's just somethin' about that last little bitta steam that finishes the magic. A squirt from a package of ketchup is applied just before eating.
*If you've never made a scrapple cheesesteak, I suggest you go get the stuff you need and try it. No matter which meal you try it for.