Heat a grill or grill pan to medium-high. Clean and lightly oil hot grill. In a medium bowl, whisk together olive oil, garlic, and lime juice. Add fish and turn once to coat; let sit 5 minutes. Remove fish from marinade, letting excess drip off. Season with salt and pepper and grill until flesh is opaque throughout, 12 minutes, flipping once. With a fork, break fish into large pieces and serve with tortillas and [salsa fresca](http://www.xanthir.com/recipes/showrecipe.php?id=id10).