To cook the konnyaku:
1. Bring a pan of salted water to the boil, add the konnyaku and cook for 3mins. Drain the water.
2. Bring the dashi stock to the boil, add the konnyaku and simmer for 12-15mins. Turn off the heat and leave the konnyaku in the stock.
3. Slice the konnyaku diagonally into 3-4mm wide strips and score one side of each strip with a sharp knife. This creates shallow cuts which will absorb the sauce.
To make the nigiri:
Wet your hands to stop the rice sticking to them.
Take 15g of sushi rice and gently shape it into an oval ball. Repeat with the rest of the rice.
Top the rice with konnyaku and ponzu jelly, then wrap in a shiso leaf. Or place the shiso leaf between the rice and the konnyaku. Serve with lime wedges.
The recipe is supplied by