Jamien Sherwood celebrated his new New York Jets contract in the most linebacker way possible ... by engorging on an enormous cut of steak!

TMZ Sports has learned ... just two days after the 25-year-old agreed to sign a new $45 million deal with the Jets -- he and some pals hit up the world-renowned Benjamin Prime in NYC to rejoice.

We're told the footballer and his group all feasted on some signature porterhouses -- which Sherwood enjoyed with a medium temp.

The guys were there for nearly two hours ... and after they wrapped things up, we're told they left a generous tip.

As for the mood -- those at the restaurant say Sherwood and his friends were very friendly and approachable.

This, of course, is the second time a New York superstar has hit up the famed eatery to celebrate a momentous contract ... you'll recall, back in December, Juan Soto also chowed down on some meat and champagne at the restaurant after signing his $756 million Mets pact.

There's a good chance both make it back, too ... as after putting pen to paper -- the guys are now locked into contracts with their respective New York franchises for the foreseeable future.

Congrats!!