Peel the satoimo, cut into bite-sized pieces, rub with 1 tsp salt (not listed in ingredients) to remove slime, rinse under running water, and drain. Slice the onion into 5mm widths.

Pat the aburaage with a paper towel to remove excess oil, cut in half lengthwise, then slice into 1cm widths.

Add water and dashi powder to a pot, heat over medium heat until boiling, then add satoimo. Cover and simmer over low heat for about 7 minutes until satoimo becomes tender.