I love this stuff.

Ingredients:

1 rock cod filet, sliced into thin pieces
5 limes, juiced
1 large tomato
1 large avocado
1/2 sweet onion, sliced into large rings

Combine all ingredients together in a bowl then cover and place in fridge for a couple hours. The acidity from the lime will cook the fish.  Serve.

Enjoy,

Eric