Preheat the oven to 200C/400F/Gas 6.
For the pork, heat a griddle pan until smoking hot.
Rub the pork with the oil and season well with salt and freshly ground black pepper. Chargrill for 2-3 minutes on each side, or until completely cooked through (there should be no pink in the centre). Remove from the heat and set aside to rest in a warm place.
For the rösti, place the grated potato into a clean tea towel and squeeze out the excess water. Season well with salt and freshly ground black pepper.
Heat half of the butter in a small ovenproof frying pan. Place the grated potato into the pan, press down and fry until lightly golden underneath. Turn over, add the remaining butter to the edges of the rösti and fry on the other side until lightly golden.
Transfer to the oven and bake for 6-8 minutes, or until crisp.
For the spiced apricots, heat the oil in a pan and add the apricot, chilli flakes, vinegar, honey and water. Simmer gently until thickened.
For the leek garnish, heat the oil in a wok or large frying pan until very hot. Add the sliced leek, season with salt and freshly ground black pepper and stir fry until golden-brown and crisp.
To serve, place the rösti onto a serving plate and top with the pork. Spoon over the apricots and garnish with the leeks.