½ medium white onion, chopped into 1/4-inch pieces
Fresh Hot Green Chiles to Taste (usually 1 or 2 serranos or 1 small jalapeno), stemmed, seeded (if you wish) and finely chopped
12 oz. (about 2 medium-small round or 4 to 5 plum) red-ripe tomatoes, chopped into 1/4-inch pieces
2 to 3 T. (loosely packed) chopped fresh cilantro (thick bottom stems cut off)
About 2 T. fresh lime juice

Scoop the onion into a strainer, rinse under cold tap water, shake off the excess and transfer to a medium bowl. Add the green chile, tomatoes, cilantro and lime. Stir well, taste and season with salt, usually about 1/2 tsp.. Cover and refrigerate until you are ready to serve.