Rinse the rice and place in a 2-quart saucepan (or rice cooker) with 3 cups of water. Bring the rice to a boil, reduce heat to simmer, and cover the pot. Cook over low heat for about 20 minutes, until all water has evaporated.

Put the cooked rice in a large bowl to cool. Put the vinegar, sweetener, and salt in a small saucepan. Bring to a boil and turn off the heat. Add the vinegar mixture to the cooked rice and mix well.

Lay a sheet of nori down on a bamboo mat. Press one quarter of the rice evenly on top, leaving about 1-1/2 inches of nori space at the top and bottom.

Spread a small amount of wasabi across the middle of the rice. Place a strip each of cucumber, carrot, and scallion across the center of the rice, sprinkle with sesame seeds, and roll up. Slice the roll into 2-inch sections and serve with soy sauce to dip and wasabi to dash.