Prep the ingredients per the instructions above.
MIx the water and cucumber in a pitcher. Refrigerate until ready to serve.
Make the nachos: In a small bowl, combine the cumin, coriander, paprika, black pepper, and salt; set aside.
Preheat the broiler on low. Arrange the pita in a single layer on an ungreased baking sheet. Lightly grease the pita wedges on both sides with nonstick spray and sprinkle with some of the seasoning mix to season. Broil for 3-4 minutes on each side or until golden brown. Then set aside to cool.
Heat a skillet over medium heat; cook the lamb and remaining seasoning mix until the lamb is nicely browned and no longer pink. Add the garlic; cook 1 minute longer. Drain. Stir the cornstarch and broth until smooth; gradually stir into the lamb. Bring to a boil; cook and stir for 2 minutes or until thickened. Then remove from the heat. Season with salt and pepper to taste.
In a small bowl, combine the yogurt, lemon juice, and lemon zest, and season with salt and pepper.
Arrange pita wedges on a serving platter. Layer with lettuce, lamb mixture, tomatoes, cucumber, olives, onions, a dollop of hummus, and cheese. Serve with sauce. Enjoy with cucumber water.