Preheat a charcoal barbecue 40 minutes ahead of cooking or a gas barbecue 10 minutes ahead of cooking. If using a cast-iron griddle pan, heat it over a high heat, then lower the heat slightly before cooking.
Cover eight bamboo skewers with cold water and leave them to soak.
Put the minced lamb into a bowl with the onions, garlic, chilli flakes, parsley, one teaspoon of salt and some freshly ground black pepper. Mix together with your hands until bound together.
Divide the mixture into eight and mould it into long sausage shapes around the drained bamboo skewers.
For the minted yoghurt, mix the yoghurt with the mint, half a teaspoon of salt and some pepper and set aside.
For the salad, finely shred the carrots and kohlrabi, on a mandolin or on the coleslaw setting of your food processor so you get nice long, thin, crunchy strips.
Put these in a bowl with a large pinch of salt and mix together well.
Heat the sunflower oil in a small pan, add the cumin seeds and, as soon as they start to sizzle, add them to the vegetables with the lemon juice and toss together.
Brush the kofta generously with oil and lightly oil the bars of the barbecue or griddle. Cook for five minutes, turning occasionally, until browned all over and cooked through.
Spread the minted yoghurt over one large or four individual serving plates. Lay the kofta on top, garnsih with the sliced tomatoes and serve with the salad.