¼ small white or red onion, minced
1 teaspoon red wine vinegar
1 pound fresh, ripe tomatoes, finely chopped
1 to 3 jalapeño or serrano chiles, to taste, minced (and seeded, if you would like a milder salsa)
4 tablespoons chopped fresh cilantro, more to taste
1 to 3 teaspoons fresh lime juice (optional)
Salt to taste
Place minced onion in a bowl and cover with cold water. Add vinegar and let sit for 5 minutes or longer. Drain and rinse with cold water.
In a medium bowl, combine remaining ingredients and stir in onions. (If your tomatoes are full of flavor, you won’t need lime juice.) Ideally, let stand at room temperature for 15 to 30 minutes before eating so that flavors will blend and ripen.