Wipe clean the mushrooms with a damp paper towel and slice thinly. If you're using shiitake it's best to cut away the stems and not use them as they can be a little tough.

Add all ingredients to a bowl and allow to marinate, ideally for a few hours. Shiitake mushrooms will go softer quicker than chestnut mushrooms, but if you don't have a few hours, you can 'get away with' marinating for just 30 minutes. They won't be as soft, but they will soak up a lot of flavour.

Will store in a sealed container in the fridge for up to 3 days.

Top, tail, peel and large dice the parsnip.

Place the parsnip, along with the other ingredients, in a food processor and pulse until the parsnip breaks down to be 'rice-like'.

Blend all ingredients in a high-speed blender until smooth.

Will store in an airtight container in the fridge for up to 2 weeks

Place the nori sheet on a rolling mat, with the edge of both (the ones that are closest to you) lined up evenly.

Place a little of each ingredient along the middle of the rice, from left to right, being sure not to overfill it, which will make the whole thing more difficult to roll.

Pick up the edge of the nori and mat that is closest to you - the ones that you lined up evenly - and start to roll the nori forwards. Once you have everything contained, you can pull it all tight, so everything holds together when you cut it. You can see my video on Youtube here on how to roll this kind of sushi (it will open a new window you click so you still have this here to refer to.