Preheat the oven to 375 degrees F. Line 1 or 2 baking sheets with foil. Cut the pita rounds into eighths. Split each piece in two and place on the prepared baking sheet(s), with the inside of the bread facing up. Spray with the olive oil cooking spray and sprinkle with 2 teaspoons of the Greek seasoning. Bake 7 to 10 minutes, or until golden.
Meanwhile, in a large skillet, brown the ground lamb with the garlic salt and the remaining 2 teaspoons Greek seasoning. Drain and set aside. In a shallow 1 1/2-quart dish, spread the hummus on the bottom. Top with a layer of ground lamb, then the tzatziki. Layer with the lettuce, tomatoes, onion, olives and feta. Serve the dip at room temperature with pita chips.
Photograph by Kana Okada
Recipe courtesy Sandra Lee for Food Network Magazine