Preheat the oven to 200C/400F/Gas 6.
For the lamb, place the spices and salt and freshly ground black pepper into a bowl and mix well. Place the lamb into the spice mixture and turn to coat well all over.
Heat the oil in a pan over a medium heat and fry the lamb for 1-2 minutes on each side. Transfer to a baking tray and place into the oven to roast for 8-10 minutes, or until cooked to your liking. Remove and rest for three minutes on a warm plate.
For the potato cake, heat the oil in a deep heavy-bottomed pan, until a breadcrumb sizzles and turns brown when dropped into it. (CAUTION: hot oil can be dangerous. Do not leave unattended.)
Mash the cooked potato in a clean bowl with the butter and medium curry powder.
Divide the potato mixture into two and, using floured hands, shape the potato into two patties.
Place the flour, egg and milk into a clean bowl and whisk to form a smooth batter.
Dip the potato patties into the batter, then carefully place into the hot oil. Deep-fry for 3-4 minutes, until crisp and golden. Carefully remove with a slotted spoon and drain on kitchen paper.
To serve, place the lamb onto a plate with the potato patties served alongside and sprinkle with chives.