Food processor method: Cut the tomatoes into wedges and remove the white part of the core; then cut the wedges in half. Cut the onion into chunks. Peel the garlic. Remove the seeds from the jalapeño peppers. Place the onion, garlic, jalapeño peppers and cilantro in the bowl of the food processor. Add the tomatoes, cumin, 2 tablespoons lime juice and 3/4 teaspoon kosher salt. Pulse until a chunky texture forms. Taste, and if you’d like extra heat, add seeds from the jalapeños. Strain the mixture to remove excess liquid (the volume will decrease by almost half).
Hand-chopped method: Chop all ingredients and mix them together, using 2 tablespoons of the lime juice and 3/4 teaspoon salt.
Place the salsa in a serving dish and stir in the remaining 1 tablespoon lime juice and 1/4 teaspoon kosher salt. Serve immediately or refrigerate for up to 3 days.