The ghost kitchen phenomenon may have diminished somewhat since the early days of the Covid-19 pandemic, but the idea of a delivery and to-go-only restaurant still draws talented chefs who want to focus on food at a lower overhead than a traditional brick-and-mortar. One of those chefs is Sunny Bertsch, whose restaurant Kaisen Sushi Houston is already drawing buzz from inner loopers looking for a more affordable, at-home sushi experience.

Located at the Blodgett Food Hall in Third Ward, Kaisen Sushi serves typical nigiri, maki, and temaki (hand rolls), along with a steak bowl. Prices are a little lower than what someone would find at a typical sushi restaurant, with an eight-piece nigiri set priced at $18.99 when ordered through the Blodgett Food Hall website (expect to pay more if ordering via a third-party delivery service such as Uber Eats or DoorDash).

While Bertsch’s food may be familiar, his story is not. The diners who’ve rated Kaisen with 4.9 stars on Google may be surprised to learn that he’s only been cooking professionally for two years. As Bertsch tells CultureMap, prior to becoming a professional chef, he worked in fields as varied as aerospace and dog walking.

“I’d always been interested in cooking,” he says. “I was blessed to be born into a great Korean American family. My dad and my grandparents always cooked great food. I learned by osmosis.”

Bertsch began his career as a private chef by working for friends. He built his business by catering lunches to powerhouse law firm Vinson & Elkins. Eventually, his clients asked for private sushi dinners, and he had to figure things out.

“I got an opportunity to do a sushi omakase. It was brutal. It was messy. But I knew once I did that, I wanted to dedicate my life to sushi,” he says. “Since then, I have studied and practiced. I threw a lot of money and time and fish at it.”

Bertsch improved his speed and knife skills by taking a $13-per-hour job at Japanese grocery store Seiwa Market. While there, he says he made thousands of pieces of nigiri, rolls, and sushi bowls. That experience, along with meals from similar to-go-only concepts in New York and San Francisco, convinced him to open Kaisen as a ghost kitchen.

“So far, I’ve spent $90,000. That’s more than the average investment for a food hall kitchen,” Bertsch explains. “I’m a clean freak. I’m a technology freak. I’m an authenticity freak. I outfitted my kitchen in the way I thought was necessary for long-term success.”

Just as he spared no expense in specing out his kitchen, Bertsch puts thoughtful touches into his food, too. For example, every order of nigiri comes with a dipping sauce Bertsch makes himself from low sodium soy sauce, kombu, vinegar, and sake.

“It’s a complex sauce that’s less salty and tastes good,” he says. “You know when you don’t have it and you’re given cheap soy sauce.”

Similarly, his California rolls use imitation crab (as do most restaurants), but it’s seasoned with a housemade, Japanese-style kewpie mayo, freshly squeezed lemon juice, and sesame oil for more umami and less sweetness. Since the chef uses more crab mix than other restaurants do in their rolls, Kaisen’s California roll not only tastes better — at $11.99, it’s a better value, too.

The chef showcases Japanese techniques and Korean influences with his $25 steak bowl. A USDA Choice ribeye or strip is cooked sous vide with a marinade made from garlic, tamari, and seasoning salt. Once a diner orders the entree, the steak is seared in a pan, basted with Kerrygold butter, seasoned with furikake and sesame oil, and served with short-grain sushi rice and microgreens from local farm Zero Point Organics.

Word of mouth has been building. Even though it’s only been open for a month, Kaisen already has over 2,000 followers on Instagram. Once he’s able to hire a full roster of cooks, Bertsch plans to expand the menu and offer lunch service. Despite some challenges, he’s pleased with the restaurant’s progress.

“The support I’ve gotten on social media has blown me away,” he says. “It’s been amazing. I could not have done it without Instagram. It blows my mind.”