Instructions In a large skillet, brown the lamb over medium heat, breaking it apart with a wooden spoon.Once cooked through, drain off most of the fat, then stir in the onions, oregano, rosemary, garlic powder, salt and black pepper to taste. Continue to cook for 5 more minutes, or until onions are translucent and lamb becomes golden brown and crispy. Set aside.To make the sauce, whisk together the yogurt, lemon juice, olive oil and garlic in a small bowl. Season to taste with salt and thin to desired consistency with water, one tsp. at a time.To assemble the nachos, line the bottom of small individual pizza pans (or a large sheet pan) with the pita chips. Spoon the lamb mixture over the top, then sprinkle with the feta cheese. (You can broil the pans for a minute or two to soften the cheese if you like.)Top with the tomatoes, cucumbers, olives, garlic sauce and parsley. Serve immediately.