Remove any bones from the fish.
In a resealable plastic bag, combing cilantro leaves, olive oil, fish sauce, soy sauce, lime juice, garlic, and red pepper flakes. Swish it around so it mixes, and place the fish in. Let marinate in the fridge for 30-60 minutes.
Meanwhile, make the sauce by combining the lime juice, fish sauce, sugar, garlic, jalapeno, and cilantro in a small mixing bowl. Stir together until combined.
Preheat an outdoor gas grill to high heat. Lay down a piece of foil to cook your fish on.
Remove fish from bag and discard marinade. Cook fish for 3-5 minutes per side until it flakes easily from a fork.
Serve hot with sauce drizzled over.