Add the coconut milk, lemongrass and grated ginger to a medium saucepan over medium heat. Let the milk reduce by half, until it’s thickened and creamy.
Add a 2 tablespoons toasted coconut and a teaspoon of fresh cilantro. Continue to simmer the sauce for about 5 minutes longer. Taste for seasoning, adding salt and pepper as needed.
Gently toss together the remaining cilantro and fresh pineapple, adding a squeeze of fresh lime.
For the Fish:
Pre-heat the grill to 400°F.
Brush the fish with olive oil and then dust with salt and pepper. When you are ready to grill your fish, soak a paper towel with veggie oil. Using grilling tongs, rub the oiled paper towels over the grill grates.
Place the fish on the grill, turning down the heat to medium so it doesn’t burn. Flip the fish only once, or it will fall apart. Cook until desired doneness. Transfer the fish to individual plates or a platter. Squeeze with fresh lime.
Ladle a little sauce over the fish and then top with the fresh cilantro and pineapple. Sprinkle with toasted coconut and enjoy!