01 - Heat grill to medium-high temperature, approximately 400°F.
02 - Lightly brush olive oil on both sides of each watermelon wedge, then season evenly with sea salt and black pepper.
03 - Place seasoned wedges on the preheated grill and cook for 2-3 minutes per side until distinct grill marks form and the fruit begins to caramelize.
04 - Transfer grilled watermelon to a serving platter. Drizzle with fresh lime juice, then sprinkle with lime zest and chopped cilantro. Add chili flakes if desired.
05 - Serve immediately as a refreshing side dish or light appetizer.