Chop the tomatoes, onion, cilantro, and jalapeño into small, uniform pieces for a smooth salsa texture.
In a mixing bowl, combine the tomatoes, onion, cilantro, and jalapeño. Stir well to incorporate.
Add the white vinegar, lime juice, sugar, garlic powder, salt, and cumin (if using). Mix thoroughly.
Cover the bowl and refrigerate for at least 30 minutes to allow the flavors to meld together.
Taste and adjust salt, lime juice, or vinegar as needed. Serve with breakfast tacos, burritos, or eggs for a tangy, flavorful addition.