He sided with Pat's in the Pat's vs. Geno's debate.
Now he's siding with the roast pork vs. cheesesteak.
Because he fell in love.
"The subtle interplay between the pork and the tart greens, between the provolone and the spices in the juices, is heaven compared with the sledgehammer-like cheesesteak."
"Going from cheesesteaks to roast pork sandwiches was like listening to whatever pop music was on the radio, and one day discovering a station that played Sinatra and Duke Ellington," he gushed.
Warren also sampled the sandwich at John's Roast Pork and DiNic's, but pronounced Tony Luke's the best.
But is Warren to be believed?
On the one hand, others have agreed.
"It's time to retire the greasy, overrated cheesesteak and name this superior sandwich our official food," wrote Inquirer columnist Karen Heller last June.
"The roast pork Italian with aged provolone and broccoli rabe is one of the finest treats the culinary world has to offer," she declared.
Tony Luke told the Washington Post many of his customers agree.
And so did Gourmet magazine once, as quoted by tonylukes.com: "Philadelphia is famous for its sandwiches: hoagies, chili-sloughed Texas wieners, steak lubricated with molten Cheez Whiz. But nothing compares to the roast pork sandwich at Tony Luke's."
Then again, Warren may not be fully informed, just like Gourmet apparently was confused about those wieners.
If a Tony Luke's cheesesteak was his basis for comparison, well, that's a worthy opponent, most locals would agree.
On "best cheesesteak" lists, Tony Luke's often finishes high, along with the likes of John's Roast Pork, Chink's and others.
But not Pat's or Geno's.
They're basically tourist traps, many here agree.
The biggest giveaway of Warren's gnawing naivete, however, is this remark: "Sharp provolone vs. Cheez Whiz? Please."
Uh, dude, you can put provolone on a cheesesteak.
Indeed, most locals prefer provolone or American, according to a Philly.com poll.
That Cheez Whiz stuff?
Popular at touristy Pat's and Geno's, and probably a big gooey part of the reason Warren dissed cheesesteaks as "gloppy."
Contact staff writer Peter Mucha at 215-854-4342 or firstname.lastname@example.org.