Shrimp tempura nori roll. You will need a bamboo mat.
Boil some sushi rice (such that all the water gets evaporated, no draining). Once it boils, cook on low for a while. Use a wooden spoon to transfer the rice into a non-metal bowl. Once it cools, per one cup rice, add about 3 tablespoons of rice vinegar, a sprinkle of salt, and two spoons of sugar. Stir it into the rice with a wooden spoon and set it aside. Meanwhile, make some tempura batter by mixing a cup of flour with a cup of beaten egg and a cup of cold water (or buy some tempura batter!). Dip shrimp in the batter and fry in hot oil for 30 seconds. Set the shrimp tempura aside.
Slice a cucumber length-wise into quarters, and slice up some avocados as well. Now place the bamboo mat flat on the counter, and put cling-wrap on it. Now lay down a nori sheet (shiny side down) on top of the covered mat. Wet your hands and use them to put and spread half a cup of rice evenly onto the nori sheet - wet hands will prevent the rice from sticking to your hands. Make sure the rice covers all corners except for a centimeter from the right edge of the nori sheet. Now on the left side edge, place a long slice of cucumber, a few slices of avocado, and shrimp (lined from top edge to bottom). Put a thin drizzle of mayonnaise (or peri-peri mayo, or Japanese mayo) on them. Now it's time to roll from the left edge to the right. Grab the cling-wrap and bamboo mat on the left side, slowly roll over the filling, and keep rolling to the right, making sure the nori overlaps over itself - keep a hold on the cling-wrap and mat, don't let them become part of the roll! Slice up and serve immediately with dipping soy sauce and wasabi!