Peel sweet potatoes and slice them into large chunks.

Boil plenty of water in a pot and cook the sweet potatoes until they are soft, for about 15-20 minutes.

Drain sweet potatoes and put them in a medium bowl. Mash them with butter and Katakuri Powder while they are still hot.

Once mashed, make ping-pong size balls with your hands. Then, press the mochi balls down a little bit so it becomes flatter, like a small cheese wheel.

Heat frying pan with cooking oil over medium heat. Pan fry the mochi and cook both sides until lightly browned.

Pour in soy sauce, mirin, sake, and sugar to caramelize.

Place mochi on a plate and garnish with a little bit of shichimi togarashi.