Barbecued whole red snapper with sea salt and fresh oregano mix and black olive & feta cheese relish

Ingredients

• 2 whole red snapper, about 450g each, scaled and gutted
• 2 lemons, cut into 1/2-cm thick slices
• 1/4 bunch fresh oregano sprigs, plus 2 tbsp. chopped oregano leaves
• Greek olive oil, plus extra for drizzling
• 1 tbsp. sea salt
• Freshly ground black pepper
• 150g chopped and pitted kalamata olives
• 150g crumbled feta cheese
• 1 lemon, juiced
• 3 tbsp. olive oil
• Salt
• pepper