Step 1 - Clean the piures, removing the membrane that covers their flesh. Also remove the dark part inside. Reserve in cold.
Step 2 - Separately, chop the onion into cubes, and cilantro leaves.
Step 3 - Place the piures on a plate or in the same bowl and add the onion, cilantro and lime separately so that each person can mix them together at the time of serving.
Step 4 - Season with salt and oil according to taste.