Mix achiote paste (you should be able to find it in a Mexican or international market) with citrus juices. Cover all surface of the fish. Place in refrigerator and let sit for at least two hours. Light grill and get a medium flame. Oil grill and place fish skin side down. When fish is about half way done (about 5 minutes) turn and continue cooking another 3 minutes. The fish is done when the juices start boiling. You should be able to lift the central bone out easily when the fish is cooked. Top with heated salsa.
The traditional Mexican way to cook fish is to place it on a banana leaf. If you can find them, wash the leaf and place on grill while it's still wet. Then add the fish. This is an old trick to keep the fish from sticking to the grill and falling apart when you try to turn it.
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