In a large bowl combine the mahi mahi, shrimp, serrano peppers, salt, pepper, and cilantro. Cover with the lemon and lime juice. If the juice does not cover all of the fish and shrimp add more to completely cover them.
Cover and place in the refrigerator for 1-4 hours depending on the doneness you prefer. Stir every hour.
Once the desired doneness has been reached add all of the remaining ingredients except the avocado and mix. then gently fold in the avocado.
Best served chilled.
Notes
Consume within 48 hours of making it storing in an air tight container. Mahi Mahi can be replaced with cod, halibut, albacore, tilapia, red snapper, or sea bass.