Add all ingredients to the slow cooker. Use a spoon to crush the whole tomatoes and stir everything together.
Cook on low for 6-8 hours or high for 3-4 hours.
Remove any fresh herb stems. Then blend to your desired consistency with an immersion blender, or leave it chunky.
Before serving, taste and adjust seasonings.
Notes
Store leftovers in an airtight container in the refrigerator for up to 5 days, or freeze for up to 3 months.*Yield: about 8 cups sauce, 1 serving = ½ cup.