Prep all ingredients per the instructions above.
Prepare the Sushi Rice: Rinse sushi rice under cold water until the water runs clear. Combine the rinsed rice and water in a saucepan. Bring to a boil, then reduce the heat to low, cover, and simmer for 15-20 minutes, or until the rice is tender and the water is absorbed.
In a separate bowl, mix rice vinegar, sugar, and salt until dissolved. Transfer the cooked rice to a large bowl and while it's still hot, gently fold in the vinegar mixture until the rice is well seasoned. Allow the rice to cool to room temperature.
Prepare the Philadelphia Roll: Lay a bamboo sushi rolling mat on a clean surface, covered with plastic wrap. Lay a sheet of nori, shiny side down, on the plastic-covered mat. Spread a thin layer of sushi rice over the nori, leaving about 1 inch at the top edge.
Place salmon slices, cream cheese, and cucumber matchsticks on the rice. Roll the bamboo mat firmly to shape the roll.
Repeat to make more rolls, then slice each roll into bite-sized pieces.
Prepare the Miso Soup: In a saucepan, heat the dashi over medium heat. Dilute the miso paste with some hot dashi in a bowl to create a smooth paste. Stir the diluted miso paste into the dashi.
Add tofu, green onions, nori, and mushrooms to the soup. Simmer for 2-3 minutes, avoiding boiling. Taste and adjust seasoning.
Serve Philadelphia roll with soy sauce, pickled ginger, wasabi, and miso soup. Enjoy with fortune cookie and coconut water!