Peel the carrots and slice thinly using a mandoline to about the width of matchsticks, place in a bowl with the lime juice, sugar and salt and mix thoroughly.
Heat the oil in a pan over a moderate heat, add the onion and mustard seeds and cook until the seeds start to sizzle, then pour over the carrots, mix well and set aside.
Remove the membrane from the scallops, and clean thoroughly.
Combine the curry powder, sugar and salt in a bowl, and then roll the scallops in the mix and coat the scallops all over.
Heat a pan and add a splash of olive oil, place the scallops into the pan and sauté for about 2 minutes on each side until they are golden brown, firm to the touch, and cooked through.