In a large bowl, combine the fresh fish cubes and lime juice.
Cover and refrigerate for at least 1 hour, or until the fish is opaque and "cooked" by the lime juice.
While the fish is marinating, prepare the diced tomato, cucumber, red onion, red bell pepper, and green bell pepper.
Drain the marinated fish, discarding the lime juice.
In a large mixing bowl, combine the marinated fish, diced tomato, cucumber, red onion, red bell pepper, green bell pepper, and green chilies (if using).
Pour the coconut milk over the fish and vegetable mixture.
Season with salt and black pepper to taste.
Mix gently to combine all the ingredients.
Transfer the Ota Ika to a serving dish.
Garnish with fresh cilantro or parsley if desired.
Enjoy your meal!