Place 1 sheet of nori lengthwise on a bamboo mat, shiny-side down. Position the sheet about 1-inch from the side of the mat closest to you. Wet your hands in cool water and take a handful of sushi rice.
Place the rice in the center of the nori and use your fingers to spread the rice evenly across it. Next place the asparagus, goat cheese, and prosciutto horizontally across the roll. Use the mat to roll up the sushi, pinching and squeezing the mat to shape it into a round cigar shape. Slice into 1-inch thick rolls with a sharp knife. Turn rolls onto their sides so the rice is facing upwards, and serve with pickled ginger, wasabi, and soy sauce.
Place the water and salt in a medium sized saucepan and cover it with a tight-fitting lid. Bring the water to a boil.
Add rice, return to a boil over medium heat, and then reduce heat to low and simmer. Once the water has evaporated from the rice, remove the pan from the heat. Stir in the rice vinegar and let cool before using.
