Here are my opinions:
Judges:
Gordon Ramsay: Ti-ISTj
Joe Bastianich: Ti-INTj
Graham Elliot: Si-ESFj
Contestants:
Whitney Miller: Te-ISTp
David Miller: Se-ESFp
Sheetal Bhagat: Fi-ISFj
Lee Knaz: Si-ISTp
Sharone Hakman: Te-ESTj
Mike Kim: Fe-ISFp
Jake Gandolfo: Si-ESTj
Tracy Nailor: Fe-ESFj
Slim Huynh: Ne-INTj
Tony Carbone: Ne-ENFp
Not sure about the rest of the contestants:
Faruq Jenkins: ?
Jenna Hamiter: ?
Sheena Zadeh: ?
Avis White: ?