1 1/2 pounds fresh fish cubed
1 1/2 cups fresh lime juice
1 pound fresh tomatoes chopped
1 1/2 cups finely chopped onion
2 serrano chile's seeded and finely chopped
1 clove garlic, finely chopped
1 teaspoon dried leaf oregano
3/4 cup chopped cilantro leaves
1 small can sliced black olives (optional)
1/4 cup olive oil
1 ripe avocado finely chopped
Salt and pepper to taste

Marinate the fish in lime juice and cover in a non metallic container
for at least 5 hours, stirring occasionally.
Drain and discard liquid. Combine remaining ingredients and mix with fish.