Wash the rice until the water is clear. Drain the rice. Carefully boil up with 125 ml water in a pot. When the rice is boiling, close the pot with aluminium foil and a lid. Cook on low heat for about 10 minutes. Leave to swell for another 10 minutes on the switched off hotplate. (It is important to keep the rice covered so that it can swell in its own steam).
Mix tempura flour, egg yolk and 1⁄4 l cold water. Do not stir too hard, the dough may be lumpy. Put it in the fridge, then it will be nice and crispy when baked out.
Place the finished rice in a large bowl, drizzle the sushi mix over it and fold in with a moistened wooden spoon. Let the rice cool down a bit, but process it as warm as possible
Wrap two bamboo mats in cling film. Cut nori leaf in half lengthwise. Halve washed half cucumber lengthwise, remove seeds and cut into thick sticks. Halve avocado, remove stone and peel half an avocado and cut into slices. Use the second half for other purposes
Place each 1⁄2 nori leaf on the bamboo mat with the rough side facing upwards. With moistened hands, spread half of the sushi rice (preferably still warm) evenly on top, leaving about 2 cm free at the top. Place a second bamboo mat on top. Now turn everything over so that the rice is at the bottom. Remove the upper bamboo mat with the foil
Place pieces of cucumber and avocado next to each other as wide strips in the middle of the nori leaf. Roll up firmly with the help of the lower bamboo mat, but do not wrap up the foil. In this way make two square rolls. Mix the sesame seeds and turn the rolls over. Cut each roll into 8 pieces
Heat the oil in a wide pot to approx. 180 °C (it is hot enough as soon as bubbles rise from a wooden skewer). Meanwhile, rinse the shrimps in cold water, dab them dry and pull them through the batter with a fork. Fry in hot oil for 3-4 minutes, turning occasionally. Drain briefly on kitchen paper, mix while still hot with the mayonnaise so that it melts. Serve immediately on one Sushi each