Uncovering the secret sauce at Le Relais de Venise, a Parisian steak frites powerhouse.

I came to Paris on a whim this weekend, with a last-second airline ticket and a hastily-packed bag (a reminder that the real reason I live in Barcelona is that a half a dozen of the greatest cities in the world are never more than a few cocktails and a haphazard decision away). I came to Paris because the last time I was here, 13 years ago, I had just enough money to buy a $1 bottle of wine to drink in front of the Eiffel Tower; it turned out to be vinegar. I came to Paris because I spend half the year on the road and my girlfriend deserves a bit of romance. But if I’m being completely honest, I came to Paris to eat meat—the redder the better.

There are lots of ways to get a red meat fix in this town. Boeuf bourguignon and cote de boeuf and $27 hamburgers dominate the menus of every bistro, brasserie and café in Paris, and you can’t toss a baguette without landing on a chilly cylinder of beef tartare. But as our plane broke through the dense cloudbank and a city of lights sparkled below, there was just one dish on my mind: steak frites.

Meat and potatoes. As elemental as fire and water, yet the French have a way of making even the most rudimentary combinations feel like something only their particular brand of fastidiousness could formulate. Enter Le Relais de Venise, a restaurant that communicates its steak frites seriousness by offering no menu at all: everyone who eats there will be served the same cut of beef, the same stack of fries, the same token salad. Relais has gone international in recent years, washing up on the shores of London and Manhattan to remind the English-speaking world that it was the French who perfected this combination first. Let’s be clear: Le Relais de Venise does not make the best steak frites in Paris, but when you arrive on a Saturday night only hours after buying a plane ticket, you go directly to the best possible place that doesn’t take reservations.

Clearly we weren’t the only ones with this strategy in mind. The line snaked ominously around the block. We waited 30 minutes, then left the hordes and the freezing temperatures to fortify ourselves with wine and absinthe. We came back at 10:45 to find the line as long as when we left it. This time we stuck it out to the bitter end.

Moments after you sit down, one of the dozen waitresses, all of them dressed like turn-of-the-century servants, arrives with a giant silver platter and a scowl stained on her face. The feast has begun. She lays out the beef first: domino-size slices of entrecôte (a rib eye, essentially), jiggly-rare, burgundy throughout. Next to the meat is piled a golden haystack of potatoes, the exact same size and shape of McDonald’s fries, but with a creamy-crisp dynamic that the Golden Arches (even back in the day when they were frying in beef tallow) could only dream of. Then, finally, comes the big moment: a ladle of a mysterious sauce that blankets the beef and seeps into the potatoes and turns everything into a glorious mess.

“The sauce is like a drug,” my girlfriend said after a few bites. That is not the first time those words have been uttered in these parts. Relais’ sauce is the object of much desire, and much speculation. A Le Monde food writer a few years back boldly proclaimed to have cracked the code: ground chicken livers, cream, thyme, and mustard. The restaurant vehemently denied the Parisian paper’s recipe, and after my meal on Saturday night, I will echo the denial. My best guess is a béarnaise (egg yolks, reduced vinegar, and melted butter whisked into golden ribbons of emulsified fat) tweaked with garlic and tons fresh tarragon and probably a bit of Dijon. Whatever it is, it would make old shoe leather something you dream about for days.

The meat could be better—could be beefier, could wear a deeper, more consistent char instead of a few timid grill marks—but I don’t know if you’d notice it under the weight of the emerald bath of butter and herbs. Anyways, beefiness is beside the point. Relais is jam-packed with French people, they are not the French of the cultural clichés, the ones who sit around dinner tables until the sun comes up picking intermittently at the rich bounty before them and staying wafer thin along the way. These are people on a mission for base sustenance. At Relais de Venise, the din of conversation is drowned out by the scraping of silverware and the grunts of hungry hungry humans. And by the time you’re finishing your plate, a waitress is there to pile on more potatoes, and pour on more of that sauce. No one in the room will have consumed less than 2,000 calories by the time they lumber, having accomplished their task, back into the night.