The best thing you never heard of is called colatura di alici, or garum, its ancient name.

Garum and other similar fish-based sauces were the ketchup of the ancient world, mass produced in factories by the Romans, and sprinkled on anything savory. They usually made several versions: a dark-colored table condiment that was high in protein, a cooking sauce similar to Thai and Vietnamese fish sauces (sometimes called liquamen by historians, though often grouped together with garum), and a milder version called muria, explains food historian Sally Grainger. The fall of the Roman empire meant the end of its mass production, but the art of the fish sauce was not lost in Italy. The modern-day version, colatura di alici, is a saltier mixture of all three sauces.

While Italy may not be the first place that comes to mind when thinking of fish sauce, several companies on the Amalfi coast continue the ancient traditions. Today’s colatura is a clear, amber liquid made from fermented, salted anchovies and sold in tiny, elegant glass bottles. It is often described as the great-grandfather of Worcestershire sauce. “There is only a difference of a few ingredients, but colatura tastes better,” Grace Singleton, managing partner at Zingerman’s Delicatessen, tells me.

Photograph: zingermans.com

Zingerman’s, based in Michigan, started carrying the condiment around 15 years ago, when co-founding partner Ari Weinzweig found himself in the Amalfi coast town of Cetara, where it has been made for generations. After tasting it for the first time, Weinzweig knew he had to carry it in his store. It took a year to get all the labelling right for US importation, but it was worth it. Since then, the sauce has had a steady following, Weinzweig tells me.

Everyone who has tried it remembers the exact moment when colatura di alici and taste buds first met. For Matt Armendariz, who runs the food blog Matt Bites, it was in Italy, in an aioli sauce. “My mind was blown. It had this umami flavor and I asked the chef why it was so delicious, and he said he used colatura di alici. I just fell in love with it,” Armendariz fondly recalls.

The amber sauce, which is fermented traditionally in chestnut barrels, is an inexpensive way to add depth and flavor to dishes, says Singleton. A little glass bottle will set you back on average $15, but you only need a sprinkling to bring a new dimension to food.

It is also the key to a quick and simple pasta dish popular in the Amalfi coast. Any kind of long, thin pasta is mixed with garlic, chili-infused olive oil and a little colatura di alici for an unmistakable savory rich flavor that belies its simple ingredients. Armendariz recommends sprinkling it on ripe tomatoes or putting a few drops on grilled steaks and other meats to make the flavor pop. Singleton favors using it in place of salt in dishes, since it does double duty by both salting a dish and accentuating its flavors.

Despite its fishy origins, don’t think of it as a fish sauce, says Armendariz, who refers to the flavor enhancer as a “genie in a bottle” on his blog. It’s a true secret ingredient for the modern age, taken straight out of the ancient world.