When the current COVID-19 lockdown was announced, second-generation sushi master Tomoyuki Matsuya set about cheering up his customers the best way he knew how: through the warmth of good food and high-end chirashi zushi – a blanket of sushi rice beautifully decorated with seafood, herbs, vegetables and the occasional flower.

"I wanted to showcase my family's craft through the chirashi for guests who missed authentic Japanese food, and also for those who missed out on their omakase reservation at the restaurant due to unforeseen cancellations," says Matsuya, who was serving a $230 multi-course omakase menu at Chatswood wagyu temple Choji Yakiniku before lockdown.

Matsuya's chirashi box is a vibrant chequerboard starring tuna belly, kingfish, sea urchin, spanner crab, octopus, truffle, shiso leaf and many more delicacies. The chef's 11-year-old daughter, More, was a key collaborator on its design, drawing a "map" for the chirashi that her father references daily.

"My daughter and I are very close so she understands me well. It was easy for Mone to visualise the image I had in my mind by drawing out my description. She then helped me to plan a nice contrast between each seafood through her colouring … and yes, she made it very pretty!"

Matsuya is one of many sushi masters offering premium raw fish through lockdown. Japanese chefs across Sydney have created their own chirashi and omakase-at-home sets that are (for the most part) much easier to secure than a seat at one of their booked-out sushi counters.

Chef Chase Kojima (Sokyo at The Star) was pivotal in starting the chirashi trend when he launched takeaway-focused Simulation Senpai last year. The Darling Square eatery specialises in handpicked seafood beautifully scattered on seasoned rice and luscious bowls of raw tuna, salmon and wagyu.

"During the first lockdown, I started making some cool-looking sushi dishes and posting them on Instagram," Kojima says. "People quickly started messaging me to ask if I was selling them. Simulation Senpai came about because there was so much demand for high quality sushi at home.

"It also meant I could provide work for my chefs while restaurants were closed. When this lockdown hit, I noticed a lot of my friends with sushi restaurants started offering similar takeaway options. They understand that this is food people still want to eat. It's a little bit of luxury – a bit of self-care."

That sushi is especially luxe at the moment thanks to an outstanding southern bluefin tuna season, says John Susman, managing director of seafood sales and marketing company Fishtales. Because Japan isn't importing as much Australian-caught bluefin as usual (for reasons including the Olympics host's own coronavirus outbreak), plenty of the fatty fish is available for the local market.

Seafood fans keen to try their own hand at sashimi can easily find the prized tuna at Sydney Fish Market. "Any of the vendors should have some, but my tip for bluefin is Claudio's because it has such a huge Japanese and Korean contingent of food service and retail customers," Susman says.

"These days all the decent shops at the markets have a bespoke sashimi section, though. Choose a little block of bluefin and the staff will slice it wafer-thin or thick depending if you prefer Tokyo or Osaka-style sashimi. You don't need to be too worried about having the knife skills of Tetsuya Wakuda or Chase Kojima."

Bluefin tuna direct from the markets is also offered for home delivery through growing business GetFish. 200 grams of bluefin sashimi costs $15 and is available whole or sliced, while salmon, cuttlefish and ocean trout attract similar prices.

"There has been a significant increase in sashimi sales since lockdown as customers now have an increased opportunity to try the product," says GetFish founder Antonio Muhollo. "Once people are introduced they are hooked on its quality and freshness. The northern suburbs in particular have really jumped on the sashimi bandwagon."

Five deluxe sushi options for lockdown

Next Gen Chirashi Zushi, $70, Choji Yakiniku

Almost too pretty to eat. Tuna belly, imperador and tamagoyaki omelette are surface-level highlights, but there's a lot to love in what lies beneath. "The key to making a great chirashi is to use Japanese sushi rice and aged red-rice vinegar," says Chef Matsuya. Available Tuesday to Friday, pick-up only. Visit chojiyakiniku.com.au to order. 228 Victoria Avenue, Chatswood.

Hachioji Omakase Set, $100, Hachioji

Chef Benson Pang will provide free delivery within 20km of Willoughby for orders over $200, so best order two of these sets including oysters, sashimi, nigiri (hand-shaped rice with fish), soup and dessert. Pick-up also available, call 0422 421 203 to order. Shop 2, 56-58 Frenchs Road, Willoughby.

Hoseki Bako, $55, Simulation Senpai

Chase Kojima's connections with Sydney's best fishmongers run deep, and the chef has spent a good part of lockdown sourcing high-end seafood for his signature 15-piece chirashi box. It's served over emi-no-kizuna variety rice made especially for sushi and used at many of the world's best omakase restaurants. Pick-up only, visit simulationsenpai.com to order. The Exchange, 1 Little Pier Street, Haymarket.

Premium Nigiri Box, $75, Sushi E

Merivale is on board the exclusive sushi train too, offering a chef's selection of market seafood such as bluefin o-toro, scampi and cuttlefish plus condiments. The chirashi box is also a stunner, starring lobster, scallop and salmon roe. Pick-up only Saturday. Call 02 9114 7314 to order but note that quantity is very limited. 1 Tankstream Way, Sydney.

Sushi Box, $65, Kisuke

It's difficult to score a seat at Yusuke Morita's omakase restaurant at the best of times, which means orders for the sushi master's lockdown box fill up fast. Expect 13 or so pieces of sterling seafood for $65. Follow Kisuke's Instagram to know when orders open each week. Pick-up only. 50 Llankelly Place, Potts Point.

Other high-end sushi heroes offering limited takeaway

Azuma Level 1, 2 Chifley Square, Sydney, azuma.com.au

Harada 18A Wentworth Street, Glebe, harada.net.au

Kuon Omakase Shop 20, 2 Little Hay Street, Haymarket, kuon.com.au

Yebisu Bar & Grill Level 1/55 Dixon Street, Haymarket, yebisubargrill.com.au

Gold Class Daruma The Grace Hotel, 77 York Street, Sydney, goldclassdaruma.com.au