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Kumamoto Oysters with Ponzu Granita and Tobiko

This sophisticated seafood starter pairs the natural sweetness of Kumamoto oysters with a vibrant, citrus-led ponzu granita. The combination of Japanese yuzu, mirin, and soy sauce creates a refined dressing that highlights the delicate salinity of the shellfish. Topped with a touch of tobiko for a subtle crunch and a pop of colour, it is a beautifully balanced dish that brings a touch of professional fine dining to your home kitchen.

As a diabetes-friendly option, this light appetiser focuses on high-quality protein and fresh, aromatic herbs rather than heavy fats or sugars. It is an excellent choice for a summer dinner party or a special celebratory meal where you want to offer something both healthy and indulgent. Serve the oysters nestled on a bed of fresh seaweed to maintain their temperature and provide a stunning coastal presentation.

Continue reading below

Ingredients for Kumamoto Oysters with Ponzu Granita and Tobiko

  • 1 (1-inch-wide) piece kombu (dried kelp), rinsed

  • 240ml water

  • 45ml mirin (Japanese sweet rice wine)

  • 45ml soy sauce

  • 45ml rice vinegar (not seasoned)

  • 2 tablespoons fresh or bottled yuzu juice

  • 1 teaspoon sugar

  • 18 small oysters (preferably Kumamoto or Prince Edward Island), not shucked

  • 30g tobiko (flying-fish roe)

  • 1 oyster knife

  • Garnish: a bed of seaweed (450g)

  • a protective glove

  • an oyster knife

How to make Kumamoto Oysters with Ponzu Granita and Tobiko

Bring kombu and water to a simmer in a small saucepan over moderate heat, then remove from heat and cool completely, about 30 minutes. Discard kombu. Transfer 80ml kombu broth to a bowl along with remaining granita ingredients and stir until sugar is dissolved. (Reserve remaining broth for another use.)

Pour granita mixture into an 8-inch metal baking pan and freeze, stirring and crushing lumps with a fork every 20 minutes, until evenly frozen, about 1 hour. Scrape with a fork to lighten texture, crushing any lumps.

Wearing protective glove, hold an oyster, flat side up, and open it at its narrow point with oyster knife. Loosen oyster from top shell with oyster knife if necessary, discarding top shell, then loosen oyster meat within curved bottom shell, keeping it in shell. Discard any loose bits of shell. Arrange oyster on bed of seaweed and repeat with remaining oysters in same manner.

Top each oyster with a scant 1/4 teaspoons tobiko. Serve granita on the side.

Disclaimer

While every effort has been made to ensure the information is accurate and up to date, individual needs may vary and dietary requirements can differ based on personal health conditions. Always check food labels and allergen information before preparing or consuming any recipe. If you have specific health concerns, allergies, intolerances, or are following a medically prescribed diet, seek advice from your GP, pharmacist, or a registered dietitian before making significant changes to your diet or lifestyle.

Article history

The information on this page is peer reviewed by qualified clinicians.

  • 17 Jan 2026 | Originally published

    Authored by:

    UK recipe editors

    Peer reviewed by

    UK recipe editors
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