For the rice, rinse in cold water until the water runs clear then soak for 30 minutes in fresh water before draining well and then adding to a rice cooker with equal part of water and cook.
Blend the vinegar, sugar and salt together and set aside.
Transfer the hot rice onto a hangiri, pour the sushi vinegar over and with a big spoon, use a cutting motion to mix the vinegar through the rice evenly. Use a fan to cool the rice quickly to room temperature and store in a sealed container until needed.
For the kinshi tamago: whisk the eggs in a bowl with the sugar and salt. Heat a non-stick frying pan over medium heat and spray with oil. Spoon a little egg mix into the pan and swirl to make a thin sheet and cook until set, only seconds, then flip to cook other side and transfer to a plate. Repeat with rest of egg then thinly slice the egg crepes into strips.
Spoon the rice into a large sushi rice bowl, scatter with the kinshi tamago, sashimi, prawns, cucumber, lemon, nori, roe and avocado. Serve with wasabi and soy.