the rest of the mystery layover revealed

Since elaine and adam knew it was Newark, New Jersey, here are some more details in case you want to visit. The name for the neighborhood is Ironbound. You can read about it here or here.

There was quite a large selection of Portuguese and Spanish restaurants from the small cafes to upscale places, so given the option again, I would definitely go back.

The closest train station? Newark Penn Station (not to be confused with New York Penn Station), and it is served by the fine folks at NJ Transit who run the local/regional NJ trains such as the one I took from the airport, Amtrak if you're coming from further away, or PATH if you're coming from the NYC side.

So you want to travel from Newark Liberty Airport to the Ironbound neighborhood of Newark, New Jersey? If you want to make a daytrip like me from the Newark Airport, it's very simple. Follow the AirTrain signs inside the airport and buy your ticket from the machine using paper money, coins, or a credit card from the NJ Transit ticket machines. It costs 7.50 each way, so buy 2 one way tickets to get there and back. Go upstairs and get on the AirTrain and get off at the RailLink which is the second (and last) stop. It comes after P4 parking. The AirTrain goes in two directions, so when you're getting on, make sure you get on in the right direction.

Use your ticket to get through the turnstile and go down the stairs to the platform. Wait there for one of the regional trains heading toward north toward NYC. (You cannot get on an Amtrak train, your NJ Transit ticket is only good for NJ Transit trains.) They are clearly marked on the schedule on the TV monitor in the waiting room, or look for a train that is silver with orange/brown rather than silver with red/blue (Amtrak). There are two NJ Transit lines coming through, the Northeast Corridor or the New Jersey coast line. Both stop at Newark Penn Station so hop on either one.

You are only going one stop to Newark Penn Station and it takes 5 minutes. The trains toward NYC are often crowded, but don't worry, people will stand in the aisles and such and you're only going one stop. Get off at Newark Penn Station. You want to walk toward Ironbound and away from the business district. The area outside Newark Penn Station has Ironbound clearly marked. If you happen to walk out an exit where you don't see an Ironbound directional sign, then continue to follow the perimeter of the train station building as there are clearly marked signs in existence.

Give yourself perhaps 5 to 10 min max depending on which exit you came through to reach the edge of the neighborhood, and then walk around and enjoy.

Overall timings from the airport:
--Leaving baggage claim you need from 5-20 min depending on where you are to go back up one escalator and find your way to the ticket machine.
--You need from 5-15 min to get a ticket, depending on if there are people in line in front of you.
--You need 10-12 min to wait for the AirTrain and then take the ride to the Rail station.
--Another 3 min and you'll be on the platform.
--Depending on the time of day, you may wait from 10-40 min for an NJ Transit train. These trains may often be 20 min late, so factor that into the equation.
--Then 5 min on the train and anther 5-10 min to be in the neighboorhood.
So depending on the timing of everything you may be door to door in an hour as I was, although I had budgeted 1.5 hours to get there. I had done the same for the return trip, so I'd say you'd want a four hour layover or more to make your travel worth the effort.

Assuming you have a painfully longer layover, rather than going to Newark Penn Station, you can instead go to New York Penn Station, just follow the above instructions and your ticket will instead cost 15 USD each way and you will be on the train longer, until New York Penn Station, the end of the line at around 40 min. Then you're on your own to find good Portuguese food!