Bobby Flay does the 500º burger

Bobby Flay may be sick of burgers -- and we all may be sick of burger stories -- but here's one more:

Flay, who opened Bobby's Burger Palace in University City on Tuesday to hour-long waits, stepped out for a late-afternoon field trip.

Destination: 1504 Sansom St., home of rival burger operation 500º, which opened March 23.

Owner Rob Wasserman spotted the chef on his way in and bought him a meal. When pressed for specifics, Wasserman said it was a 500º burger (medium), plus black-and-white shake, and fries.

Cordial chat. Flay likes talking about burgers and business.

"I didn't expect to eat anything, but the owner was nice enough to buy me a burger and fries," Flay told me later by e-mail. "He's doing a nice job."