Karaimo Nettabo (Sweet Potato Pounded Mochi)

Peel 600g sweet potato and cut it into 3cm pieces. After a 5-minute soak in cold water, drain the pieces well. Spread them in a steamer without piling them up and cook over medium-high heat for 18 minutes. When a skewer can almost pass through the sweet potato, place 200g mochi pieces over the top without letting them touch one another. Steam for another 7 to 10 minutes. Move on when the skewer reaches the center of the potato freely and the mochi has softened enough to stretch. Transfer both ingredients to a pounding bowl before they cool. Wet the pestle and pound for 8 to 10 minutes, turning the mass as needed, until no white mochi pieces or separate yellow potato lumps remain. The dough should have one continuous color and texture, with no visible pockets of either ingredient. Mix 50g roasted soybean flour, 50g sugar, and 1g salt across a wide tray. Dampen your hands, divide the warm dough into eight portions, and roll every surface in the kinako mixture. Set the coated pieces apart so they do not stick together and cool them for 10 minutes. The coating should dry the tacky exterior while the center remains soft and stretchy. Mochi requires careful eating: cut each portion into small bites and chew slowly. Make still smaller pieces for children and older adults and supervise them while they eat.