Marinate the lamb in the dry spices, lemon, garlic, rosemary and 100ml of the olive oil for at least 2hours but preferably overnight.
Cut the cucumber in half lengthways, scoop out the seeds and cut into a large dice. Cut the feta and red onions into similar size pieces. Cut the cherry tomatoes in half and roughly chop the olives. Mix all of these salad ingredients together. Roughly chop the mint and parsley and add to the salad. Dress the salad with the lemon juice and olive oil and season with salt and pepper.
Remove the leg of lamb from the marinade season vigorously with salt & pepper and throw onto the grill over some moderate coals. The lamb will take about 30 min to cook so if your fire is too hot it will burn on the outside before cooking internally. I will leave the degree of doneness to your own taste personally I like my lamb cooked medium. When the lamb is ready remove it from the heat and rest it for at least 10 min.
While the lamb is resting throw the pita breads on the coals for a couple of minutes.
When the lamb has rested slice it across the grain into nice thin slices. Cut the pitas across the top to make a large pocket then stuff a few rocket leaves into the bottom of each pita. Follow this by a good spoonful of the Greek salad. Poke a few juicy slices of lamb into the pita and give a hearty dollop of hummus. The addition of pickles chillies or some Tzatziki at this stage is optional.