Put the courgettes in a sieve and press down to extract as much liquid as possible. Transfer to a bowl.
Heat a dry heavy-based frying pan until hot, add the sesame seeds and cook, shaking constantly, for 1–2 minutes until golden brown and aromatic. Add to the courgettes, together with the lamb and all the remaining ingredients, except the oil and lemon wedges. Season liberally with salt and pepper.
Form the mixture into 20 small balls. Heat a shallow depth of oil in a frying pan, add the koftas, in batches, and cook for 5 minutes, turning frequently until evenly browned. Keep the cooked koftas warm in a preheated oven, 160°C (325°F), Gas Mark 3, while you cook the remainder. Serve hot, garnished with lemon wedges.