Place the cubed fish in a non-reactive glass or ceramic bowl.
Pour the fresh lime juice over the fish, ensuring all pieces are fully submerged.
Cover the bowl and refrigerate for 15 to 20 minutes, or until the fish becomes opaque and firm to the touch.
Drain approximately half of the lime juice from the bowl to prevent the dish from becoming overly acidic.
Add the sliced red onion, diced tomato, cilantro, and minced jalapeno to the bowl.
Drizzle with olive oil and season with salt and pepper.
Gently fold the ingredients together using a spatula to avoid breaking the fish pieces.
Serve chilled immediately with tortilla chips or crackers.