When Josh Brawer announced to his parents what he and three friends were planning for their senior project at Lower Merion High School, the reaction was skeptical.

"C'mon," said Josh's father, David. "You're going to go around eating cheesesteaks for a month? You've got to be kidding me."

To David Brawer, the projects tended to divide the high school seniors into two groups. There were the kids who'd take the month off before graduation to do something socially active, such as work for a charity or a political campaign. And there were the others, who'd do nothing but hang out at the old man's office.

In other words, the do-gooders and the slackers.

Josh's cheesesteak adventure sounded - at least in the beginning - suspiciously as if he'd be joining the ranks of the latter. It sounded like a scam.

But it didn't seem silly to me when I was asked to mentor this project. Josh and his classmates Andy Shore, Jeffrey Steinberg and Tommy Conry would become my eating team.

After all, they were trying to answer one of the great culinary questions of our time: Who makes the best cheesesteak?

Talk about ambition. No food has defined our region more than this double-fisted roll of gusto. Nothing cuts across class lines, or bonds the generations with more unifying power, than a steaming-hot steak "wid" or "widout." (That's wid onions, if you have to ask.) The topic is an endless obsession, from gym locker rooms to the pages of the local media to Steinberg's car every time he and his buddies headed out of school for yet another lunch-period steak adventure.

Which is the best? Settling this question (at least once, though probably not for all) is a matter of regional preoccupation and a rite of gastronomic closure for these four friends about to leave for college. But it wouldn't be easy. Before it was over, the journey would take us more than 110 miles, through two states, 23 steakeries, 65-plus sandwiches and countless hours of challenging digestion.

In four days.

Ever since the first time my dad took me to Geno's, we have shared an incredible bond. During the car ride home, we began to argue over what really made the steak. I believed that it was the Whiz, while he claimed that the Amoroso's roll was integral. Apparently, we were both wrong.

- Josh Brawer's cheesesteak diary

The anatomy of a cheesesteak would appear simple enough - roll, meat, cheese and toppings. But how would we know the merely good ones from greatness?

My new students were experienced in the ravenous joy of attacking a juicy sandwich. I could see that the moment we met:

Josh, the shy devotee of Classic Coke who loved to reminisce about his favorite cheesesteaks.

Jeff, the loquacious sophisticate, who had honed his palate during family dinners at the Palm.

Andy, who wasn't going to let the cast on his arm from a basketball mishap get between him and a sandwich.

Tommy, the meticulous note-taker and future plastics engineer.