While the exterior of The Backhouse is nondescript and unassuming, its creator, story and food are anything but. Behind the veil of a ghost kitchen, chef Jui Nguyen is the woman behind the curtain serving up high-end sushi takeout.

The Backhouse is just one of many restaurants housed in the San Mateo Food Hall offering takeaway meals out of a shared space. What makes The Backhouse unusual is its takeout offerings, serving omakase to go. While omakase, a meal in which the chef chooses the courses, is often served in an exclusive setting, Nguyen brings this experience to the comfort of customers’ kitchen tables. Omakase dining is often an event reserved for a special occasion at a fine-dining establishment; Nguyen realized, however, that this option is not available for every family.

“The ones that have kids that can’t really go to those high-end restaurants,” she explained. In contrast, her restaurant offers omakase to go “so they can enjoy it with their families. I think the one thing that everyone sees right now is that they can get that omakase experience at home,” she said, “giving them that sit-down experience.”

It wasn’t always this way for Nguyen. She’s relatively new to the landscape of Japanese food, with little formal training. But this lends to an interpretation of Japanese food that is wholly her own. After a three-year stint at a Japanese restaurant in San Francisco, Nguyen created her own concept of the modern sushi eatery.

“I did work at a restaurant for three years — that’s where I learned the techniques,” she said, “(but when) I started The Backhouse, it was just me testing out recipes.”

Nguyen experiments with dry-aging her fish and adding nontraditional garnishes. Unique toppings for her dishes include squid furikake on scallop sushi, Parmesan cheese on fatty tuna, garlic pesto on salmon and peach-ginger jam on shima aji and kamasu, as well as red pepper jelly and Korean melon oroshi on kinmedai. Nguyen also incorporates seasonal truffles into her repertoire — currently, the black burgundy variety.

“I get to create my own way of presenting sushi (other) than the whole traditional Edomae style,” she said, referring to the strict, customary way of preparing sushi that originated in Tokyo during the 19th century. While Nguyen trained in the Edomae style at her previous job, she quickly learned to uncover flavors outside the norm.

Once a family has its sights set on takeout, it has several unique creations of Nguyen’s to choose from based on group size and tastes.

In addition to a 10-piece chef’s-choice omakase bento box ($75), Nguyen’s sushi takeout offerings include nine to 13 pieces of salmon, tuna and mixed bentos, as well as a sashimi omakase and bara chirashi (an assorted sashimi bowl). While her most popular omakase dishes include salmon, uni (eel) and toro (fatty tuna), she prides herself on two of The Backhouse’s specialties, the bara chirashi and scallop sushi.

“The chirashi has a lot of flavors in one bite,” she said. “It’s a lot of fun stuff put together.” And to her, the scallops, which often come as part of the omakase bento, are truly one-of-a-kind. “The topping that we use for it is different and it really brings out the scallop paste,” she explained.

Larger groups can choose the party platter, which serves two to eight people and comes with a variety of different fish. As a colorful array of seafood arranged in a neat, circular box, this can serve as an alternative to the individual bento box and allow different family members to choose their favorite types of fish. Additionally, Nguyen offers a do-it-yourself hand roll kit. The kit comes with negi king salmon, spicy mayo scallop, California roll-style filling, tuna, rice, nori, cucumber, takuan (daikon radish), ginger, wasabi and house soy sauce. At a price of $75, the kit makes roughly 15-20 rolls.

Nguyen occasionally makes deliveries to other locations in the Bay Area, such as San Francisco, San Jose and Hayward. In addition to sushi and sashimi takeout, diners can also inquire about dine-in pop-ups ($165 per person) or private events ($235 per person) with Nguyen serving as private chef in the latter option. However, Nguyen notes that these services are currently limited.

For now, she is focused on her omakase and bento boxes and is currently exploring a standalone brick-and-mortar location for The Backhouse, the next chapter in the restaurant’s story.

The Backhouse, 66 21st Ave., San Mateo (inside the San Mateo Food Hall); 650-260-3961, Instagram: @thebackhousesm. For same-day orders, Nguyen suggests texting to verify that she can accommodate the order. thebackhousesm.