For yoghurt tahini dressing, combine yoghurt, garlic and tahini in a bowl and stir to combine, whisk in olive oil in a thin stream and season to taste with sea salt and freshly ground black pepper.
Combine lamb, egg, mint, lemon rind, currants and spices in a large bowl. Season to taste, then fry a piece of the meat mixture and taste for seasonings, adjust if necessary and mix until well combined. Roll mixture into golf-sized balls. Place balls onto metal skewers.
Meanwhile, heat a char-grill pan or barbecue on medium high. Add skewers and grill until just cooked (5-6 minutes). Serve flatbreads with koftas, feta, tabouli, drizzled with olive oil and lemon wedges squeezed over.