Lamb kofta kebabs

Ingredients

• 900g/2lb lamb mince
• 2 onions, finely grated
• 6 garlic cloves, crushed
• 2 tsp dried chilli flakes
• 1 small bunch of flatleaf parsley, chopped
• oil for brushing
• 2 vine-ripened tomatoes, thinly sliced
• salt
• freshly ground black pepper
• 200g/7oz Greek natural yoghurt
• 2 tbsp chopped mint
• 2 large carrots, peeled and halved
• 2 kohlrabi, peeled
• 2 tbsp sunflower oil
• 4 tsp cumin seeds
• 4 tsp lemon juice