A recipe that I got from my mom.
 1 cucumber
 1 tomato
 1/4 of an onion
 some green onions
 some fresh cilantro
 salt/peper to taste
 Peel and finely dice cucumber.  Finely dice 
 tomato and onion. Cut green onions and cilantro
 into small pieces.  Mix all the ingredients.  
 Salt and pepper to taste.