Cut into quarters:
3 tomatoes
Using your thumb, push all the seeds and soft water parts out. (You are removing the seeds and liquid so that the juice of the tomato does not compete and dilute the flavor of the lime juice.) Finely dice what is left of the tomatoes and put in a medium bowl.
Finely dice into the bowl:
½ onion
Add:
15 ml chopped fresh cilantro
juice of 1 lime
salt
If desired, seed and mince finely, adding to the bowl:
1 jalapeño pepper
Stir and enjoy on corn chips or over other Mexican dishes.