Cook your millet with 2½ cups of water. Steam it or use the absorption method. This should take about 20 minutes.
In a hot fry pan, toast sesame seeds until golden. Make sure you remove them from the pan before they burn. Cool slightly then mix through the millet.
In a bowl mix together the tahini, ginger and lemon juice. Add water if your mixture looks like its curdling, to get it to a thick paste a bit like yoghurt.
Lay out your nori sheets shiny side down. Place about ½ cup millet on the nori and with wet hands press it down. Leave about 2 cm on the edge farthest away from you. Spread tahini mixture, about 1 tbsp on and add a few slices of cucumber, avocado and spring onion. Roll up and cut into 6-8 pieces. Serve with tamari and wasabi as a dipping sauce.