Soak 8 wooden skewers in lukewarm water at least 30 minutes before cooking (or use metal ones).
Peel and grate the apple, then squeeze the excess juice out.
Put the apple and lamb in bowl.
Finely chop the mint/parsley, then add to the lamb.
Add the minced garlic, cumin and coriander. Season to taste.
Using your hands, mix all the ingredients together, then shape the mixture into 8 rugby ball-shapes.
Carefully push a skewer through each koftas, then press the meat tightly around the skewer.
Put the koftas on a plate, cover with cling film and rest in the fridge until you're ready to cook.
Grill, griddle or barbecue the koftas on a medium heat for 8-10 minutes until cooked through, turning them a few times.
Whilst the koftas are cooking, grill or barbecue the pittas until they puff up. Cut pockets into them, then fill with koftas, lettuce and yogurt or other zingy sauce of your choice.