Stem and seed 2 serrano chiles (or leave seeds, depending on how spicy you want this to be). Chop 1 white onion and 2 garlic cloves. Core, seed, and chop 5 roma tomatoes. In a small heavy-bottom saucepan heat 2 Tbsp. olive oil over medium until hot but not smoking. Add chiles and onion; cook until onion is translucent but not browned. Add garlic and tomatoes; cook about 10 minutes or until vegetables look stewed. Transfer to a blender. Cover and puree. Return puree to pan; simmer over low 10 minutes or until reduced by a third. Add 1/4 cup chopped fresh cilantro and 1 tsp. sea salt. Add more salt if needed. This salsa is usually served hot. Store in an airtight container in the refrigerator up to 5 days. Makes about 1 1/2 cups.