Serves 4 (serving size: 4 shrimp, 5 okra pods, 3 tomato slices, 2 corn pieces, and about 2 tablespoons dressing)
1. Preheat grill to high heat.
2. Combine buttermilk, mayonnaise, 2 tablespoons oil, 2 tablespoons chives, dill, vinegar, 1/2 teaspoon pepper, and 1/4 teaspoon salt in a bowl, stirring with a whisk.
3. Combine remaining 1 teaspoon oil, honey, and shrimp in a small bowl; toss to coat. Thread shrimp onto 4 (6-inch) skewers. Thread okra pods onto 4 (6-inch) skewers. Lightly coat shrimp, okra, and corn with cooking spray. Place shrimp, okra, and corn on grill rack coated with cooking spray. Grill corn 14 minutes, turning occasionally. Grill okra 4 minutes on each side. Grill shrimp 3 minutes on each side or until done. Cut corn crosswise into 8 pieces.
4. Place tomatoes on a large platter; sprinkle with 1/4 teaspoon salt and 1/4 teaspoon pepper. Arrange shrimp, okra, and corn over tomatoes. Drizzle with dressing; sprinkle with remaining chives, remaining 1/4 teaspoon salt, and remaining 1/4 teaspoon pepper.