Place the oil and curry paste in a large bowl, add the lamb and mix well together. Heat a large frying pan and stir-fry the lamb for 2-3 mins. Add the peppers, onions, continue cooking and season. Mix the salad leaves with a little extra oil and lemon juice. Pile into the pitta bread. Top with the lamb slices plus the pepper and onion mixture.
Serve with a spoonful of greek style yoghurt or mayonnaise.