Step 1. Cut the fish into ½-inch cubes and place in a deep bowl; add the lemon juice and stir until the fish is fully coated. Cover the bowl with plastic wrap and refrigerate until the fish turns opaque, about 1 hour.
Step 2. Meanwhile, add the onion, garlic, cilantro, and olives with the tomato sauce and mix well. After the chilling time, combine the fish with the rest of the ingredients, stirring carefully until well coated. Serve cold with Zambos Ceviche plantain chips as a side.