California crab rolls

Name: California crab rolls
Prep time: 15 min
Total time: 15 min
Cuisine: Asian, Japanese
Ingredients: 500g sushi rice; 4 tbsp sushi vinegar; 1 ripe medium avocado, halved and stoned; juice of ½ lemon; 4 sheets toasted sushi nori; meat from 2 small dressed crabs (or 240g tinned white crab meat, drained); 1 tbsp sesame seeds; 2 tbsp sushi ginger, to serve; a squeeze of wasabi, to serve; 6 tbsp soy sauce, to serve