You can't get a table. Silvio Berlusconi would be denied a table. Francesco Totti, one of Rome's favourite footballing sons, would struggle to find a place. It's booked out, there's no chance.
I'm about to walk away disappointed when the gruff guy behind the cash register points at the bar. "You can sit there," he says, jabbing a chubby finger in the air. "If you like."
I like. This place is a dream: Salumeria Roscioli in the heart of old Rome. You know how it's almost impossible to find a decent, local-friendly restaurant in the touristy parts of Rome? This is the antidote.
I found it by chance, and this will be a night marked by chance. By good fortune.
Pounding the cobbled streets of old Rome, past ruins, past palaces, past cathedrals, past row upon row of tacky tourist restaurants with their colourful menus and supposedly wood-fired pizzas - it can get disheartening. You could go across the river to Trastavere, but that would mean losing the atmosphere of an ancient town.
So you keep on wandering the old paths, hoping for something that catches the eye, something that will kill the hunger pains without killing the illusion of being a real Roman in this perfect town. Down past the Vittorio Emanuele II monument, wind around the Pantheon, stroll through Campo de' Fiori. And it's here that I see Salumeria Roscioli.
It's not kitsch. Through the window you can't see any red-and-white checked tablecloths or tuxedoed waiters. There's no sign out the front proclaiming English menus or featuring photos of the food. All that's visible is a huge deli counter housing rows of cheeses and cured meats, a wall full of wine bottles, and tables packed with people. Italian people. That's when I walk inside and ask about a table.
The guy at the register just spreads his arms glumly, taking in the diners, the tables, the lack of empty seats: "Tonight we are full." But there's always the bar, so I take a seat.
It's not even a bar, but a ledge above the deli counter. I'm reading the menu while a guy in front of me slices a roll of mortadella that's the size of a tree trunk. Someone else is shaving a block of parmigiano-reggiano cheese. There's a burble of excitement in the air.
There's only one other guy squeezed up at the bar, and he's eating alone as well. He looks up from his salad and inclines his head. "Is this your first time here?" he asks in a thick accent. I nod. "Well, welcome, you will like it. I come here every single night - this place is like my mother."
From an Italian, that is a high compliment indeed.
His name is Stefano, it turns out, and he lives just around the corner. This is his kitchen. He goes back to his salad, and I go back to the menu. A waiter in perfectly cut clothes appears, takes my order, deciphering my hopeless Italian. Stefano picks up on the accent. "Are you from Australia? Sydney?"
"I love Sydney! Maybe you know my friend from there, Maurice?"
Ha, I'm thinking. Of course I know Maurice. He lives on Wallaby Way, right? People say this sort of thing all the time, like Australia is a small village. But Stefano isn't done.
"He is a chef in Sydney. Maurice Terzini? I think he owns some restaurants. We always eat together at Roscioli when he's in Rome."
OK, so it turns out I do know Stefano's friend Maurice. Well I don't know him, but I know of him. He runs half of foodie Sydney. I'd happily have him as my mother. This is another good sign.
Pretty soon the waiter brings over a glass of wine and a plate of the mortadella and parmigiano, gripping my shoulder as he sets it down, nodding as if he's passing on a secret. I get to work on the mortadella; Stefano tucks into a steak with rocket and olive oil. He glances over every now and then, making sure I like it.
I like it. All around there's action. The guys behind the deli counter are still slicing meats. A coffee grinder whirs. There's the clunk of used grounds being knocked into a bin. Waiters shout in Italian.
This is why people get hooked on travel. It's the sheer unpredictability of it. You don't know where you'll end up today, you don't know what you'll eat.
Sometimes these wanderings end in mediocre pasta and the company of bum-bag-toting tourists.
Other times it ends like this, with a deli, a counter top, a guy called Stefano, and a kitchen that serves as his mother.
It's not just the company, it's the food. It's that mortadella, straight from Bologna. It's traditional carbonara, Roman carbonara, with almost-too-chewy pasta and no cream. It's stuffed squid perfectly sliced on a huge white plate.
I devour it all. Stefano finishes his steak, slams down an espresso, then pats my shoulder as he gets up to leave. "Enjoy Rome," he says. "Maybe I'll see you here again tomorrow." He looks around. "You should book a table."
Join Ben Groundwater on a special 10-day cycling trip to historic Myanmar in November. Click here for details.