1. Heat grill to high (450° to 550°). Put cilantro, oil, and zest and juice from 1 lime in a food processor. Pulse a few times, just until leaves are chopped. Add salt, coriander, and pistachios and process until smooth, scraping inside of bowl as needed.
2. Mix shrimp and pesto in a medium bowl, tossing well to coat evenly. Thread shrimp onto metal skewers and grill until pink, turning once, about 2 minutes on each side. Serve with slaw, tortillas, and remaining lime, cut into wedges.