Cut the raw fish up into small (1/2 inch) cubes and put in a large glass bowl or baking dish.
Add to the fish the next 8 ingredients; toss gently to combine, then cover with plastic wrap and refrigerate for about 4 to 6 hours.
Remove and add the olive oil, avocado, and cilantro; toss and serve immediately with crackers, tortilla chips, on greens, or as a condiment or side dish.
The citrus 'cooks' the fish, similar to pickling but without a vinegar taste, so you are not actually eating raw fish.