Rayu

Also called layu, this is a Japanese sesame chili oil made by infusing sesame oil with Sichuan pepper and chili pepper flakes or powder, plus often garlic and ginger. Some will add chopped green onions and fried garlic, too.

The flavor is nutty from the sesame, with an otherwise aromatic spicy numbing; the fat from the sesame oil enhances those aromatic, kicky floral qualities. You can add rayu to soups, hot pot, ramen, noodles, or marinades, and it’s also popular as a dipping sauce for gyoza. Really you can use it for whatever your personal taste dictates!

Rayu is readily available at Japanese grocery stores like Uwajimaya, but it’s also really easy to make at home. Plus, when you do that, you can adjust ingredient ratios to whatever your taste. Like it spicier? Go nuts with the Sichuan peppercorn and chili! Want something a bit mellower? Flip that around.

Homemade rayu is simple: Just heat your oil and either pour over the aromatics, peppercorn, and chilis into a heatproof jar to steep, or take your pot off the heat and throw your ingredients directly in there. (You don’t want to get the oil too hot, as sesame oil has a low smoke point — and you’re not trying to get close to that anyway.) After combining the oil and other ingredients, the residual heat allows it to infuse gently without burning the chili powder or chili flakes, which, if you’re someone who cooks with them often, knows it can be easy to do if oil accidentally gets too hot for too long.

After steeping, homemade rayu can last a couple months in the fridge.

Whether you’re looking for ingredients to make your own or the convenience of pre-made rayu, you’ll find that all at Uwajimaya.