Preheat a charcoal or gas grill for direct cooking over medium-high heat (375°).

Heat olive oil and lime juice in a 12-inch cast iron skillet on grill. Add shishito peppers to skillet; cook 10 to 12 minutes or until peppers begin to blister, turning occasionally.

To serve, transfer peppers to a serving platter. Lightly sprinkle with sea salt and lime zest; serve with lime wedges, if desired.