submitted by Queent Kat
2 cans plum tomatoes 
  (whole, no skin) liquid removed
  1/2 to 1 cup of white onion, diced
  fresh cilantro, chopped
  (has to be fresh cause dried doesn't taste as good)
  fresh lemon juice
  fresh lime juice
  1 tsp. of white vinegar or red wine vinegar (if necessary)
  jalapeno peppers or green chilies, finely chopped (if you like it hot)
  salt
  pepper (if desired)
  
Squeeze tomatoes to remove seeds. 
  Put in a food processor.
  
  Mix until tomatoes are a little chunky, depending on your taste.
  
  Add onion and mix again for a few seconds
  
  Add a tbsp cilantro, a tsp of salt, a bit of lime juice (to taste)
  and a bit of lemon juice (to taste) and mix again. Put it in a bowl. 
  
  Add a tsp of white vinegar if necessary to mellow out the tomato taste.
  
  Add lemon, lime, cilantro, salt and pepper as needed