Wash the sushi rice thoroughly and boil it in a pot with 1⁄2 l water. Cover and let it swell at low heat for about 15 minutes until the rice has absorbed the liquid. Wash and peel the beetroot and finely dice 1 tuber. Cook in 5 tablespoons of water covered with a pinch of salt for 10-15 minutes. Drain and collect the stock. Heat 3 tbsp. brew with rice vinegar, 1 tbsp. sugar and ½ tsp. salt while stirring until sugar and salt have dissolved. Fill rice into a bowl, stir in vinegar mixture. Let the rice cool down covered with a damp kitchen roll.
Cut 2 beetroot tubers into fine strips with a spiral cutter. Mix cider vinegar, honey, salt and pepper. Fold in the oil. Mix with beetroot strips and marinate for about 30 minutes.
Roast the sesame seeds in a pan without fat and remove. Sort the arugula, wash and drain. Mix mayonnaise, wasabi and lime juice and season with salt.
Divide rice into 8 portions with moistened hands. Press a hollow in the middle of each portion, add beetroot cubes and form the rice into firm balls. Arrange beetroot strips, rocket salad and balls. Drizzle with wasabi mayonnaise and sprinkle with sesame seeds.