Combine jalapeño, tomatoes and salt in a medium bowl.
Add garlic, onion and cilantro; toss to combine all ingredients.
Alternatively, salsa can be made by placing jalapeño, 2 tomatoes, garlic and salt in food processor (or blender) and pulse until well blended. Combine mixture with remaining tomato, onion and cilantro; mix well.
Notes
This will last in the fridge up to 3 days if stored in an airtight container.