Place the red onion, red bell pepper, cucumber and celery in a food processor fitted with a metal blade. Pulse processor until the vegetables are finely chopped (depending how chunky you want your gazpacho).
Add the canned tomatoes, olive oil, red wine vinegar, salt, pepper and Spicy Tomato Salsa. Pulse until uniformly blended.
Transfer to a serving bowl and stir in cilantro. Serve chilled garnished with sour cream and/or guacamole for a refreshing cold soup.