There's no cream. You never put cream in carbonara. You don't put garlic in it either. You don't put mushrooms in carbonara, or peas, or shallots, or onion, or any of the crazy additions you might find in less authentic Italian restaurants that wouldn't last more than a few seconds in the home of that delicious pasta sauce, Rome.
For a true Roman carbonara, you're allowed four ingredients: eggs, pecorino, guanciale, and pepper. That's it. Four.
So how is it that carbonara sauces can taste so different? How can there be so many varying iterations of this classic dish throughout the city that created it? And even more importantly, why is finding a truly great carbonara in Rome so hard?
You've probably already tried the bad ones. In touristy piazzas across the city, really average carbonara is churned out daily. I've eaten plenty of them, which is why this time, things are going to be different. A good carbonara makes for one of the finest meals there is. And I'm planning to track down Rome's finest.
Via dei Chiavari 21, Rome
I'm beginning my search at what could well turn out to be the winning restaurant, Salumeria Roscioli, a fancy but still traditional eatery in Campo dei Fiori that's always packed with locals and tourists. I've been here before, and I know what to expect: fat, chewy strands of al dente spaghettoni served in a creamy egg sauce studded with crunchy hunks of guanciale – cured pig's cheek, essential for a great carbonara.
To get that creamy consistency, chefs have to be able to cook the eggs just right: gently enough so that they don't scramble, and with enough cheese to make them rich and salty. Today at Roscioli they've done this to perfection. My search is off to a good start.
Via Poli 27, Rome
You mightn't expect to find tasty, authentic cuisine anywhere near the Trevi Fountain, and with good reason. This is tourist central, where bad food is almost a given. However, I've been told there's a shining beacon of goodness in among all of this tack, and it's called Angelina.
When I arrive the place is full of businesspeople grabbing a quick lunch from a pretty tasty looking buffet at the back of the restaurant. But I'm here for the carbonara, which is served at Angelina in almost comically large white bowls that take up most of the table.
The carbonara here is much different to Roscioli's version: the spaghetti is thin, and the sauce has been allowed to scramble slightly, giving it a chunkier texture. However, the taste is still extremely good. Not as good as Roscioli, but a solid entry.
Via di Monte Testaccio 97, Rome
If you want to find Rome's best carbonara, you have to cast your net wide, in this case as wide as Testaccio, the working-class-but-food-obsessed suburb about a 15-minute metro ride from the centre of Rome. There, built into the side of a hill made from shards of broken pottery left centuries ago by traders, sits Velavevodetto.
This is a restaurant that does something once thought almost criminally different with its carbonara: it serves it with short, tubular rigatoni instead of the traditional spaghetti. Controversial it may have been, but it was also successful, and many other Romans have since adopted the same technique.
Here's why. With rigatoni, hunks of that crunchy, fatty guanicale can work their way into the middle of the pasta tube, creating something of a carbonara sandwich, a rich explosion of flavour that you don't readily forget. We have ourselves a new front runner.
Circonvallazione Gianicolense 69, Rome
Well, this was bound to happen. You can do all of the research in the world, but every now and then you're going to come up with a dud. And Mente Locale is a dud. The tip-off should have come when I booked and the owner asked if I was using my Groupon voucher. My what? No, I replied.
And so I rolled up anyway at a restaurant that had clearly changed hands very recently and was relying purely upon customers using Groupon vouchers and ordering from a set menu. They were so reliant on that, in fact, that they hadn't even anticipated anyone ordering from the regular menu.
"I'm sorry," the waitress says, "we cannot make carbonara tonight. We have no eggs." This one's a colossal fail.
Via del Casaletto 45, Rome
This is my final stop, my final attempt at finding Rome's best carbonara, and it's almost one I don't want to tell you about. Da Cesare is a little suburban restaurant in the fairly unremarkable area of Casaletto. You take a tram from Trastevere to the very end of the line, and alight in a plain neighbourhood that must surely be the wrong place.
But it isn't. Underneath an apartment block down a quiet street lies Da Cesare, with its leafy courtyard dining area and its best damn carbonara in the entire world. There you go, I've lifted the lid. This is it. This is the winner. Go no further.
The carbonara at Da Cesare is served with bombolotti pasta, a shorter version of rigatoni. The sauce is perfect – thick, creamy and rich. The guanciale is mouth-wateringly crispy and fatty. The pasta is flawless. In fact the whole thing is flawless.
The hunt for Rome's best carbonara is over. Da Cesare, collect your crown. About the only loser in this quest has been Mente Locale. And my skinny jeans.
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