Prepare a charcoal or gas grill until hot, placing rack 3 or 4 inches from the heat source. Meanwhile, thread tomatoes, eggplant and lamb on separate skewers. Brush with about 2 Tbs. oil. Salt and pepper to taste and place on grill. Grill tomatoes until just charred; cook lamb and eggplant for about 10 minutes, turning once.
As skewers cook, brush the pita triangles with a bit of oil and put them on the grill for about 30 seconds on each side.
Mix all dressing ingredients together in a small bowl.
Put the lettuce, oregano and chickpeas in a serving bowl. To serve, divide the salad among 4 plates, topping each with lamb and eggplant. Garnish with the grilled pita triangles. Serve dressing on the side.