Cut fish: Cut fish into 1.25cm / ½" cubes.
Toss in lime, leave 5 minutes: Place in a bowl with onion, jalapeño, tomato, pepper and lime juice. Gently toss, then set aside for 5 minutes, mixing gently once.
Add avocado then serve! Sprinkle over salt, then add avocado, coriander and olive oil. Gently stir, then serve immediately with corn chips (see in post for other ideas).
Ceviche will be good for 20 minutes or so, then fish will start to overcook and firm up. Do not leave overnight (for food safety reasons).
