1 pound large shrimp, peeled and deveined
6 tablespoons fresh lemon juice, divided
2 teaspoons olive oil, divided, plus additional for brushing grill
3 tablespoons chopped fresh dill, divided
1 tablespoon chopped fresh oregano
3/4 cup low-fat Greek yogurt, divided
2 garlic cloves, minced and divided
2 cucumbers (about 1 pound)
Black pepper, to taste
1 pint cherry tomatoes (about 1/2 pound)
1 small red onion, cut crosswise into 1/3-inch-thick rings
4 whole-grain flatbreads
8 small romaine leaves (optional)
1. Preheat grill.
2. Rinse shrimp, and pat dry. Stir together 2 tablespoons lemon juice, 1 teaspoon oil, and 1 tablespoon each dill and oregano in a medium bowl. Add the shrimp, and toss to combine. Marinate, stirring occasionally, 10 minutes.
3. Stir together 1/4 cup yogurt, half of garlic, 2 tablespoons lemon juice, and 1 tablespoon dill in a serving bowl. With a vegetable peeler, cut cucumbers into lengthwise ribbons, discarding the largely seeded core. Toss cucumber ribbons with yogurt mixture and pepper, to taste.
4. Combine the remaining 1/2 cup yogurt with remaining 2 tablespoons lemon juice, remaining 1 tablespoon dill, and remaining garlic in a small serving bowl for raita sauce. Season with pepper, to taste.
5. Toss tomatoes and onion with remaining 1 teaspoon olive oil in a bowl. Grill shrimp with tomatoes and onion in a lightly oiled well-seasoned cast-iron skillet or grill pan, turning once, 5 minutes or until shrimp are bright pink and cooked through, tomatoes are softened, and onion is golden brown and tender. Transfer to a plate; cover and keep warm.
6. Grill flatbread until golden brown and slightly crisp. Transfer to 4 serving plates; top evenly with cucumber salad, shrimp, onions, tomatoes, and romaine, if desired. Serve with raita sauce.