Wash the Sweet Potato well. Leave the skin on the sweet Potatoes and slice them into discs 2cm thick. Soak them in water for 10 minutes and drain well. (Soak immediately after cutting to remove scum)

Combine water and sugar in a frying pan and add sweet potatoes. Cover with a drop lid and heat.

Bring to a boil, turn heat to medium and simmer for 10 minutes. When half-cooked, add Salt and Mirin. Simmer about 8 minutes until tender.