Chop tomatoes, discard seeds, and place in a bowl.
The following can be easily done by pulsing a food processor: Peel and dice onions, remove seeds of chilies under running water and dice (be careful to avoid burns, use gloves if necessary).
Mix chopped vegetables with remaining ingredients besides the water. Pack firmly into quart sized mason jars, adding filtered water if the juice does not cover the vegetables.
Salsa should be at least 1 inch below the top of the jar.
Cover tightly and allow to sit at room temperature for 1 day before transferring to the fridge.