HEATH Ledger isn’t letting any grass grow under his feet. Just a week after announcing his split from Michelle Williams, Ledger has been squiring Danish pastry Helena Christensen all over town. Tuesday night, the two were at Wakiya “making out throughout the dinner,” our spy said. Acting like a good boyfriend, Ledger even “held her bag for her as she did interviews.” The two then went to the after-party for the movie “Eastern Promises” at the Soho Grand, and ended up at the Spotted Pig.