Melt butter in a non-stick frying pan. Add onion and saute for 2 minutes. Add curry powder and cook for 1 minute.
Add rice, chives, yoghurt, salt and pepper, prawns and lemon juice. Stir well to combine.
Spoon 3 tablespoons of the mixture onto wraps. Fold well to enclose filling and cook until crisp using a café style grill.