Place onion, jalapeno pepper, cilantro, lemon juice, and six of the tomato quarters into the Vitamix container in the order listed and secure lid.

Select Variable 1.

Turn machine on and slowly increase to Variable 5.

Blend for 15-20 seconds, using the tamper to press the ingredients into the blades.

Reduce to Variable 3 and remove the lid plug. Add the remaining tomatoes through the lid plug opening.

Blend for an additional 10 seconds or just until desired consistency is reached, using the tamper to press the ingredients into the blades. Do not over mix, leave chunky. Serve with tortilla chips.