Season the fish with salt.
Cut a 50g block of unsalted butter into small pieces
Bring a large sauté pan to the stove and once hot drizzle olive oil.
Cook the fish to a golden colour over high heat, then flip and repeat.
Reduce the temperature to medium.
Add butter and baste the fish for 5mins.
Remove the fish and place on a tray or a plate.
Take the caramelised onions and warm in the same sauté pan.
Add the fish back into the pan.
In a small pot warm up the onion amazake with the wild onion pearls.
Remove the fish from the pan and plate.
Scatter onions over.
Garnish with the nasturtium leaves.
Pour over some toasted rice oil.