1. In a mixing bowl, combine the beans, bell pepper, mango, 1/2 cup of scallions, and cilantro with 1/2 cup of the Tropical Vinaigrette. Refrigerate for at least 30 minutes or up to 6 hours.
2. Prepare a medium-hot barbecue fire or preheat a broiler. In a shallow dish, toss the shrimp with the remaining Tropical Vinaigrette. Refrigerate for 15 to 30 minutes. Thread the shrimp onto metal skewers and grill, turning once or twice, until lightly charred on the outside and cooked through, 4 to 5 minutes.
3. Divide the spinach among 6 plates. Spoon the bean and mango salad onto the spinach, top with the shrimp, and sprinkle with the remaining 1/4 cup scallions.