Cut the tomatoes in half and remove the seeds. Roughly chop the red onions and the garlic cloves.
Combine all ingredients in a blender or food processor and pulse until you get a chunky consistency. Season with cumin, sea salt, and black pepper to taste. Transfer the salsa to an airtight container.
Chill the salsa for at least 1 hour in the fridge or overnight. Serve with tortilla chips and garnish with cilantro leaves.