Boil half a kettle of water and pour it over the abura-age sheets. Dunk them gently for a minute to remove excess oil.
Drain and rinse the aburaage under cold water, then carefully squeeze out the moisture without tearing them.
Add vegan dashi, sugar, and soy sauce to a medium saucepan and bring it to a gentle simmer. Stir until the sugar dissolves.
Add the prepared abura-age to the saucepan and simmer gently for 10–15 minutes, or until most of the liquid is absorbed. Use a drop lid or small heatproof plate to keep the abura-age submerged.
Allow the simmered tofu sheets to cool before cutting them into your desired shapes for sushi or other meals.
Notes
Pour boiling water over the abura-age and squeeze our excess water before cooking. This removes excess oil, and gives a cleaner flavour and helps the broth absorb properly.
Keep the heat low and gentle when simmering. A fast boil can affect both the texture and how well the tofu soaks up the seasoning.
Use a drop lid or a small plate to keep it submerged so it cooks evenly and absorbs more flavour.