Marinate ("cook") the fish. Transfer the diced fish to a large bowl. Add the serrano peppers, garlic, cilantro, and salt.

Cover with the juice from approximately 10 limes, 1 grapefruit, and 2 oranges. If your fish is not completely covered, add more lime (or lemon juice) as needed until it is.

Allow the fish to cook. Cover the bowl with plastic wrap and transfer to the refrigerator to keep cold.

Allow your fish to "cook" for 1-4 hours (see notes). Stir every hour.

Soak the shallots. Add the shallots to a separate bowl and cover with hot (not boiling) water and 2 teaspoons salt. Mix well.

Allow the shallots to soak for approximately 10-15 minutes before draining and rinsing with cold water. Cover and set aside in the refrigerator until ready to use.

Marinate the tomatoes. Approximately 30 minutes before serving (see notes) add the shallots, tomatoes, and bell pepper to a new, larger, mixing bowl.

Add the juice from approximately 5-10 limes and sprinkle with approximately 1 teaspoon of salt. Mix well to combine.

Allow the tomatoes, shallots, and bell pepper to rest for approximately 15 minutes. Drain approximately half the liquid from the bowl, cover, and set aside in the refrigerator.

Check the fish. Check the doneness of your fish. The fish should, at the very least, be completely white around the outside.

Put it together. Once the fish is ready, remove the smashed garlic cloves. Add the tomato, shallots, and bell peppers to the fish, mixing well to combine.

Stir in the chopped cilantro and olive oil and several dashes of hot sauce, if desired.