Cut the Tomatoes in half and remove the seeds. 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.
Chill the salsa for at least 1 hour in the fridge or overnight. Serve the homemade salsa with nachos and garnish with coriander leaves.