Wash, then prick the skins several times with a fork.
Rub a little olive oil over each potato and stand on some kitchen paper on the microwave turntable. 1 x 175g sweet potato will take 4-5 minutes on high (900W); 2 x 175g sweet potatoes will take 6-7 minutes on high (900W); 3 x 175g sweet potatoes will take 12-14 minutes on high (900W).
Cook on combination (microwave/fan), if you can, for a crispier skin. Try filling the sweet potatoes with garlic cheese, such as Boursin, and top with rocket.
Do not store sweet potatoes in the fridge, as this turns their natural sugar to starch and will ruin their natural flavour.