In a large bowl, combine the onion, lemon zest, lemon juice, parsley, cilantro, mint, salt, cumin, paprika, pepper, and olive oil. Add the lamb to the marinade and toss to coat. Cover with plastic wrap and refrigerate for 2 to 4 hours.

Soak 8 to 10 bamboo skewers in warm water for about 1 hour before assembling the kabobs.

Preheat the grill to high, and lightly oil the grill grates to prevent sticking. Thread the lamb onto the soaked skewers and place on the grill, turning to evenly cook, about 12 to 14 minutes.

Drizzle the pitas with sauce, then wrap the pita around the meat on the skewer, fold over and twist the skewer off the meat. Serve.

Combine all ingredients in a small bowl. Refrigerate until ready to serve.