Cook the onion base: Place a small frying pan over medium heat with a dash of oil. Sauté the onion and garlic until tender. Add the ground cumin seeds and chilli flakes and cook, stirring, for about 2 minutes. Set aside to cool slightly.
Mix the lamb: Put the lamb into a mixing bowl. Add the onion mixture, chopped parsley, chopped mint, a drizzle of olive oil and a pinch of salt and pepper. Mix well with your hands.
Shape the koftas: Roll the mixture into pieces the size of golf balls and flatten into patties about 1cm thick. Place on a plate drizzled with oil and drizzle the tops with more oil. Cover and chill for about 10 minutes to firm up.
Make the dressing: Put the mint into a mortar and bash with the pestle to bruise it. Add the yoghurt, toasted cumin seeds, black pepper and lemon juice. Mix well and adjust seasoning.
Griddle the koftas: Place a griddle pan over medium-high heat. When hot, griddle the koftas for 5 to 6 minutes, turning halfway through so that both sides are well browned.
Serve: Serve the koftas warm with the dressing on the side.
