A Gambino crime family associate who beat the rap for stabbing the owner of popular Brooklyn ​p​izzeria Lucali​ ​–​ ​​only to w​ind up behind bars for another stabbing​ ​–​ ​is now using the prison mail system to deliver threats, prosecutors said.

Battista “Benny” Geritano was back in court Thursday to face charges he’d been using the mailing system at Green Haven prison to commit extortion​ ​–​ ​but was too focused on ​a feamle Brooklyn federal ​court clerk to be arraigned under the new indictment. The objects and content of his pen-pal blackmail remained unclear.

“Can I know what her name is?” the 44-year-old ​flirtily asked, interrupting Magistrate Judge Viktor Pohorelsky as he tried to explain to the proceeding. “I need to know what her name is.”

When the judge told him the clerk’s name was irrelevant, Geritano​ ​–​ ​who’s served four years of a 12-year sentence in an all-male facility​ ​–​ ​became agitated.

“You’re in my court now,” the incarcerated mobster barked​ back, catching the judge​ off guard. “I’m a sovereign, Christian male.”

Pohorelsky turned to an equally taken-​a​back ​lawyer ​Michael Sporn, who had yet to be assigned to represent Geritano, to ask if ​he felt Geritano was competent to continue the proceeding.

“Oh I’m competent,” the twitchy inmate said, again interrupting the judge as he glanced at the clerk.

Pohorelsky ordered the marshals to eject the Gambino associate, who thrashed as three men descended on him and pushed him out of the courtroom.

“Based on his performance, I don’t think he’s ready to be arraigned,” said Assistant US Attorney Lindsay Gerdes, who successfully prosecuted Geritano as an Assistant DA in his 2012 Brooklyn Supreme court ​stabbing case.

The sinewy goon was convicted on assault charges for knifing Nunzio Fusco inside a Bay Ridge ​b​ar​ ​– just a year after he was cleared of stabbing ​Lucali owner Mark Iacono over a purported love triangle.

The Brooklyn DA’s office dropped the case after Iacono refused to testify against his former friend, who had become convinced the ​Carrol gardens pizzeria owner was trying to steal his gal pal.

Geritano is slotted to return to court Tuesday.