Attach the food processor's chopping blade. Place the quartered tomatoes, roughly chopped red onion, peeled garlic cloves, and chopped jalapeño peppers, the fresh cilantro, lime juice, ground cumin, salt, black pepper, and sugar (if using) to the processor.

Pulse the food processor in short bursts until the ingredients are finely chopped. Be cautious not to over-process; you want the salsa to retain some texture. Some prefer a chunkier salsa, while others like it smoother.

After blending, taste the salsa and adjust the seasoning as needed. Add more salt, lime juice, or sugar to balance the flavors.

Transfer the salsa to a bowl, cover it, and refrigerate for at least an hour before serving. This allows the flavors to meld.