Ingredients

• 1/2 pound plum tomatoes
• 2 fresh serrano chilies
• 1/2 cup finely chopped white onion
• 1/4 cup chopped fresh coriander leaves
• 1 teaspoon coarse salt, or to taste
• 3 tablespoons water

Instructions

1. Cut tomatoes in half crosswise and seed if desired. Finely chop tomatoes and transfer with any juices to a bowl. Wearing rubber gloves, finely chop chilies, including seeds. Stir chilies into tomatoes with remaining ingredients. Salsa may be made 6 hours ahead and chilled, covered.