For the seared scallops, heat a frying pan until smoking hot. Rub the olive oil over the scallops, season with salt and freshly ground black pepper and fry for 1-2 minutes on each side. Remove from the heat and keep warm.
For the sweet potato cake, place the chopped sweet potato into a pan of boiling salted water and boil until tender. Drain and return to the pan. Mash the cooked potato with the rest of the potato cake ingredients, except the olive oil, until smooth. Using your hands, shape into a patty.
Heat the olive oil in a pan and fry the sweet potato cake until golden on all sides. Remove from the pan and drain on kitchen paper.
For the curry oil, gently heat the olive oil, curry powder and vanilla seeds together in a pan for 2-3 minutes, then strain through a sieve.
To serve, place the sweet potato cake onto a serving plate, top with the scallops and pour over the curry oil.