Mix all the ingredients except for the oil in a large bowl until smooth. Divide the mixture into 6 and form into even-sized, sausage-shaped patties.
Make the marinade. Mix the yogurt, curry powder and garlic in a flat-based dish. Thread the patties on to oiled metal skewers and leave to marinate for 2—4 hours.
Remove the skewers from the marinade. Brush the patties with oil and cook on a medium-hot barbecue for 10—15 minutes, turning occasionally.
Serve hot, garnished with the onion, pepper and parsley, dusted over with paprika, and with lime wedges to squeeze over.