How to make
Cut the onions and tomatoes into equal sized cubes. Finely chop the jalapeno peppers, and strain the tuna and corn well from the liquid.
Put everything into a bowl, along with the coriander and chop the lettuce into small pieces. It is good to use the leaves from the core, because they are much more tender.
Squeeze the lemon, add the mayonnaise and salt and stir to mix all the ingredients evenly.
Serve the salad immediately. In case you want to prepare it for serving after more than an hour, I recommend not to add salt, lemon and mayonnaise and leave it for the moment just before serving.
Enjoy your meal!