Lay half a sheet of Nori flat on the chopping board, rough-side up. With your fingers, transfer 120 grams of cooked white sushi rice to the Nori sheet. Gently fluff out the rice to the edges of the sheet, until an even coating is achieved.Encase the bamboo rolling mat in a zip-lock sandwich bag. This will ensure the rice does not adhere to the rolling mat. Then, lift the Nori sheet with your fingers, flip it over, and lay rice-side down onto the rolling mat.Position the Nori sheet lengthways in front of you. Lay two asparagus stems horizontally across the center, with the tips slightly overhanging at either end. With clean metal tongs, add a thin layer of Shimeji mushrooms just above the asparagus – again spanning the entire length of the Nori sheet.To create the roll, simply curl up the rolling mat edge in front of you with your fingers, Manipulate it up and over, using your fingers to apply pressure along the length. Curl the bamboo mat all the way over until you reach the farthest edge of the Nori sheet. With your thumbs behind and fingers in front of the roll, apply firm pressure to seal it, and compress the contents. Move to one side.