With food processor running, drop whole garlic cloves through the chute to mince; scrape down sides with a rubber spatula. Add onion; pulse several times until finely chopped. Add remaining ingredients (crushed tomatoes through salt) and pulse to desired consistency. Taste for seasoning and add more salt as desired.
Transfer to serving bowl; cover and refrigerate at least 30 minutes before serving. Garnish with chopped cilantro if desired and serve.
Video
Notes
If using fire roasted diced tomatoes, drain some or all of the can liquid to before adding to avoid a watery salsa.
Add up to 1 additional teaspoon of smoked paprika for a smokier flavor.
Makes 4 cups of salsa. Store in the refrigerator in an airtight container for up to 5 days.