Quite possibly the best thing to come out of a jar!

I have always taken a deep pleasure in trying new foods, and I’m lucky in that I tend to enjoy almost everything. Every now and then, however, I stumble across something new that completely blows me away, instantly igniting a lifelong love affair. This happened when I tried Italian lardo, and again with creamy, oozing burrata; when I discovered bone marrow, and when I had my first bite of steak tartare. A couple of months ago, Editor Caroline sat down, deliberately placed a white-labelled jar on our desk and began raving about its contents. I grabbed a spoon. Ever since then, there has never been a moment without a jar on the desk.

White Mausu Peanut Rayu is the brainchild of Katie Sanderson, chef turned entrepreneur. While working in the renowned Fumbally Café in Dublin, “someone came in with a traditional rayu for us to sample,” she tells me. Rayu is a Japanese chilli garlic oil, often used to season bowls of rice, ramen or noodles. That day, Katie was inspired to create a version that was a bit more substantial, adding sesame seeds and peanuts. “The reaction that we got once we put it on our dishes was so strong that it created immediate demand. As soon as people tried it, they would want to buy it. It was really powerful; it just seemed to bring joy to people.”

Katie was born in Hong Kong to Irish parents, moving to Dublin when she was 12 and spending her summers in Connemara. The contrast between the intensely busy city in which she was raised and the wild quiet of Ireland’s West has shaped her as a person and as a chef. “As I get older,” she says, “I’ve found that a resurgence of inspiration from Asian flavours has crept back into my cooking.”

For a long time, she worked in traditional chef roles, including private catering and jobs in restaurants and ski chalets. “For the last eight years, though, I’ve been focusing on working with food but in ways that felt really good for me. I’ve left the long hours of restaurant kitchens behind.” These feel-good jobs have included pop-up raw food dinners, running a temporary dillisk seaweed restaurant and creating food for yoga retreats. “I’ve been kind of a floating chef,” she says.

Once she saw the reaction to the Peanut Rayu, she began selling it at Dublin markets. Her jars didn’t even have labels but, yet again, everyone who sampled it would immediately make a purchase. Katie soon realised that she would have to give her baby a name and some proper branding. “White mouse is a nickname my granny used to call me when I was little,” she explains. “Mausu is simply the Japanese word for mouse.”

These days, White Mausu is made in a little kitchen in the Food Enterprise Centre in Stoneybatter, Dublin, which has been its home for just under two years. Katie and her partner are currently running the operation with just one other person, each one of them playing many different roles. “At any given moment, I could be designing labels, actually making the rayu, jarring it — every day is different.” In addition to the rayu, they’re getting ready to launch a second product, Cashew Crunch. “That one has a similar consistency, but plays more on the contrast between sweet and salty.”

The rayu is pan-Asian, borrowing flavours from Japan, China and Korea and combining them in the perfect ratio of salty to sweet. It has a nice kick to it without being too spicy, so it doesn’t exclude those who shy away from heat, and its umami undertones keep you coming back for more. It’s also made using a high-grade tamari, keeping it suitable for those who can’t eat gluten.

“I would love to be able to source everything locally,” says Katie, “but it’s just not possible.” Instead, she is always on the hunt for other sustainable practices she can incorporate. “We use glass packaging and recycled boxes, and we are investigating whether it’s possible to convert to organic.” In addition to this, she has plans to keep growing the business in Ireland as well as testing whether the rayu would be popular overseas — if you ask me, there’s no question on that front.

Katie’s favourite way to enjoy her Peanut Rayu is over a rice bowl, or stirred through peas. “It’s a great way to boost your energy after a long shift.” Since Caroline tempted me down the white mouse-hole, I’ve discovered my own delicious ways to feed my addiction: stirred into porridge for a deeply savoury breakfast that keeps me going for hours; dolloped over cold noodles or stir-fried tenderstem broccoli; or simply eaten from a spoon for an instant hit of energy when my reserves are running low. Top-tier stuff, however, is marrying it with runny egg yolks, about which I could wax poetic for days. I’ll spare you the long, dreamy testimonial, but suffice it to say that this is truly nothing short of a perfect pairing. Check out the recipe here.

I don’t know when I’ll stumble across the next bite that thrills me, but in the meantime I’ll be keeping that white-labelled jar on my desk. (And another
at home.)