Cut potatoes into 1/8-inch brunoise cubes; rinse in cold water; pat dry.

 Place potatoes and coconut milk in saucepan. Add salt to taste. Cook over medium heat until potatoes are tender and coconut milk is reduced to a creamy thickened mixture. Drain potatoes. Set aside to cool.

 In small bowl, combine tuna, mayonnaise, kimchee and sambal. (Add caviar if using.)

 On sushi mat, place nori sheet, shiny side down. Spread potatoes over nori, covering all but 1 inch from top of sheet.

 Spread tuna mixture across center of potato mixture. Sprinkle with black sesame seeds.

 Arrange radish sprouts on top of tuna filling with some sprout tops extending beyond each end.

 Placing your thumbs on back of sushi mat, begin rolling away from you, supporting filling with fingers.

 Roll until edge of nori is under sushi roll. Shape roll by pressing lightly with both hands. Remove sushi mat. Slice roll into six pieces.

Source: Idaho Potato Commission