01 - Rinse sushi rice thoroughly under cold water until water runs clear. Combine rice and water in a saucepan and bring to a boil. Cover tightly, reduce heat to low, and simmer for 15 minutes. Remove from heat and let stand covered for 10 minutes. Dissolve sugar and salt in rice vinegar, then fluff rice with a fork and fold in vinegar mixture. Allow rice to cool completely to room temperature before assembling.
02 - While rice cools, slice prosciutto into thin strips. Cut fresh mozzarella into uniform thin strips. Slice roasted red bell pepper into thin julienne pieces. Cut sun-dried tomatoes into thin strips. Wash and dry fresh basil leaves and arugula, keeping them separate for layering.
03 - Place nori sheet on bamboo sushi mat with shiny side facing down. Moisten hands with water and spread a thin, even layer of cooled sushi rice over the nori, leaving a 2-inch border at the top edge. Arrange prosciutto, mozzarella strips, roasted peppers, sun-dried tomatoes, arugula, and basil in a horizontal line along the bottom third of the rice. Drizzle evenly with olive oil and season with freshly ground black pepper.
04 - Use the bamboo mat to roll sushi tightly away from you, applying firm but gentle pressure. Seal the edge with a small amount of water. Repeat process with remaining ingredients. Using a sharp knife dampened with water, slice each roll into 6 uniform pieces. Wipe knife clean between slices for clean cuts.
05 - Arrange sushi pieces attractively on a serving platter. Drizzle with balsamic glaze if desired and garnish with additional fresh basil leaves. Serve immediately at room temperature for best texture and flavor. Can be offered with small bowls of extra balsamic glaze on the side for dipping.