Zac Young's Donut Pop-Up; Foursquare's Most Popular Venues

MIDTOWN— Grub Street learns that Flex Mussels pastry chef and Top Chef Just Desserts alum Zac Young has opened a pop-up donut shop in Grand Central Station. He'll sell donuts for two weeks from noon to 6 PM in the take-out section of Zócalo restaurant in the lower dining concourse. [GS]

EAST VILLAGE— Some bad news, from Northern Spy Food Co.: "Disaster! Closed tonight due to frozen water pipes, troubles galore. Back tomorrow. Shit happens." [Twitter]

IRON CHEFFAGE—On last night's Iron Chef America Bagatelle chef Nicolas Cantrel defeated Iron Chef Marc Forgione in Battle Gruyere. To see clips from the battle, head over to Eater National. To taste the winning dishes, all five of his dishes will be offered starting January 31 through the month of February on Mondays - Wednesdays. Dishes can be ordered a la carte or as part of a five course prix fixe. [EaterWire]

CHECKING IN—— Social networking site Foursquare grew 3400 percent last year, and they celebrated by publishing a sweet infographic about some of the most notable check-in stats. Of interest to New Yorkers: the Union Square Greenmarket is the most checked into food destination in the world, The Ace Hotel, the most checked into hotel, and Terminal 5 is the most checked into music venue, followed by Hollywood Bowl in LA and Mercury Lounge on the LES. [Foursquare]