Rayu is a spicy red oil that is never far at hand at ramen shops or anywhere that the fried or steamed dumplings called gyoza are served.
In the last year or so, though, the condiment (sometimes seen written as la-yu) has taken center stage in a chunkier, more flavorful incarnation that has gone from foodie indulgence to the fast-food mainstream. Taberu, or edible, rayu has the same chili-infused sesame oil base as the pourable stuff, but it’s packed with minced chunks of fried garlic and onion that give it a chunky, spoonable consistency. Momoya released jars of it one year ago with a mouthful of a name that translates to “It looks spicy but isn’t too spicy but is a bit spicy” last year. When it sold out, S&B Foods released a not-so-subtle copycat version called “Pour it on! Main dish rayu, a bit spicy.” Now it’s gone well beyond grocery store shelves and is turning up as a potato chip flavor, a tonkatsu topping, and most recently, glopped on the patties at Japan’s homegrown burger joint Mos Burger.