Ingredients:

4-5 large Roma tomatoes, chopped
1/2 large white onion, chopped
1/2 cup cilantro - leaves only, chopped
Juice of 1 lime
2-4 serrano chili peppers, finely chopped (they are the approx. 3' long thin green chilies)

Mix all ingredients, chill one hour and serve. Chop the peppers last using rubber gloves or a plastic bag over your hands. Serranos range from warm to very hot so taste the salsa after adding each pepper to see if you need another.

This does not keep well so you have to eat it all immediately!