Add <quantity>⅔<unit>cup</unit></quantity> of rice wine vinegar to a saucepan over high heat

Combine <quantity>½<unit>cup</unit></quantity> of sugar with a pinch of salt and add to the saucepan. Stir to dissolve

Add a <quantity>5<unit>cm</unit></quantity> x <quantity>5<unit>cm</unit></quantity> kombu leaf

Add the juice of <quantity>½</quantity> a lemon

Bring it to a boil and stir until no grains of sugar are visible. Turn off the heat

Transfer the liquid to a container. Remove the kombu leaf and let it cool down

Trim, halve, and peel <quantity>2</quantity> large shallots

Separate the inner parts and reserve for another recipe. Thinly slice and cut the outer layers into a very small dice

Transfer the shallots to the liquid and let them sit for at least 10m to pickle. The pickled shallots are ready. Store them in the refrigerator in the liquid

Add <quantity>7<unit>tbsp</unit></quantity> of soy sauce to a bowl

Add <quantity>5⅓<unit>tbsp</unit></quantity> of mirin

Add <quantity>3<unit>tsp</unit></quantity> of rice wine vinegar

Add <quantity>3<unit>tsp</unit></quantity> of water

Add <quantity>4<unit>tsp</unit></quantity> of yuzu juice

Stir to combine. The ponzu sauce is ready

Dip the oyster in fresh cold water and pat it dry

Wash the shells, scraping off any remaining oyster muscle

Put the oyster back in the washed shell and add <quantity>1<unit>tsp</unit></quantity> of the ponzu sauce

Add <quantity>½<unit>tsp</unit></quantity> of the pickled shallots and garnish with edible flowers. The oyster with ponzu & pickled shallots is ready

Enjoy!