1. Preheat oven to 425°.
2. Combine first 7 ingredients in a food processor or blender; pulse 30 seconds or until well combined.
3. Arrange fillets in a single layer in a 13 x 9–inch baking dish. Pour lemongrass mixture over fish; turn fillets to coat evenly. Bake at 425° for 13 minutes or until fish flakes easily when tested with a fork or until desired degree of doneness. Serve sauce with fish.