Place the tomatoes, jalapeño, garlic (if using), and cilantro into the Vitamix and blend on Variable #1 or 2 using a tamper to push ingredients into the blade. Blend until desired texture is reached (I like mine a little chunky). Stir in the lime juice, chopped onions, and spices.
For the food processor:
Place the tomatoes, jalapeño, garlic (if using), and cilantro into the food processor and pulse until the desired texture is achieved. Stir in remaining ingredients until mixed.
For chunkier salsa:
If you prefer a chunkier salsa texture, chop the tomatoes, onion, cilantro, and jalapeño and combine them in a medium-size bowl. Stir in the lime juice, cumin, and salt.