In a food processor, combine cilantro, scallion tops, lime zest and juice, red-pepper flakes, spice blend, green mango pickles, oil, 1/2 teaspoon salt, and 1/4 teaspoon black pepper. Blend until smooth. Transfer to a medium bowl.
Add okra and white and light-green parts of scallions to marinade and toss to combine. Thread 8 skewers, alternating okra and scallions and ending with a lime quarter.
Preheat grill for direct-heat cooking (medium-high on a gas grill) or a grill pan over medium-high. If using grill, brush grates with oil.
Grill okra and scallion kebabs, turning a few times, until charred in places and softened, 6 to 8 minutes.