1 large Japanese eggplant, trimmed and cut into 20 1/2-inch-wide half-moon pieces
1 cucumber, seeded and chopped
1 large yellow or red bell pepper, seeded and cut into 1/2-inch chunks
1/2 cup black olives (pitted, optional)
1/2 cup diced red onion
High-heat cooking oil (such as sunflower, safflower or grape seed oil), as needed
Olive oil cooking spray
2 6-inch whole-grain pitas
2 cups lightly packed trimmed baby spinach leaves
1/3 cup reduced-fat plain yogurt
1 tbsp fresh lemon juice
1 tbsp chopped fresh mint leaves
4 metal or wooden skewers (soaked if using wooden)
In a large bowl, whisk together lemon zest, 1/4 cup lemon juice, garlic, oregano, olive oil, salt and black pepper. Transfer half of dressing to a second large bowl.
Add tomatoes and eggplant to first large bowl, tossing to coat. Let stand for 15 minutes.
Meanwhile, prepare salad: To second large bowl, add cucumber, bell pepper, olives and onion; toss well with dressing and set aside.
Prepare yogurt sauce: In a small bowl, combine all yogurt sauce ingredients. If necessary, add additional water 1 tbsp at a time until sauce reaches a pourable consistency.
Heat grill to medium-high and lightly oil grate with cooking oil. Onto each skewer, thread tomatoes and eggplant, dividing ingredients evenly among skewers. Mist skewers with cooking spray. Add skewers to grill; close lid and cook for 8 to 10 minutes, turning once or twice, until tender.
Just before skewers are finished, mist pitas with cooking spray; grill, turning once, until lightly toasted and warm, about 1 minute. Cut into quarters and divide among plates. Add spinach to salad and toss. Serve with souvlaki, yogurt sauce and pita.