01 - Rinse the sushi rice under cold water until the water runs clear. Combine rice and water in a saucepan, bring to a boil, cover, and simmer for 15 minutes. Remove from heat and let stand, covered, for 10 minutes. In a small bowl, dissolve sugar and salt in rice vinegar. Fluff the rice with a fork and stir in the vinegar mixture. Cool to room temperature.
02 - While rice cools, prepare all fillings — slice prosciutto, mozzarella, roasted pepper, and sun-dried tomatoes; keep fresh basil and arugula ready.
03 - Place a nori sheet on a bamboo sushi mat, shiny side down. With wet hands, spread a thin, even layer of sushi rice over the nori, leaving a 2 cm edge at the top. Lay prosciutto, mozzarella strips, roasted peppers, sun-dried tomatoes, arugula, and basil in a line along the bottom third of the rice. Drizzle with olive oil and sprinkle with black pepper.
04 - Use the mat to roll the sushi tightly away from you. Seal the edge with a little water. Repeat with remaining ingredients. With a sharp, damp knife, slice each roll into 6 pieces.
05 - Arrange on a platter. Optionally drizzle with balsamic glaze and garnish with fresh basil. Serve immediately.