Turn on the slow cooker and let preheat while gathering the ingredients.
Dice the onions, mince the garlic and grate the carrot
Add the olive oil, onion, garlic, and grated carrot.
Pour in the crushed tomatoes.
Add the dried basil and red pepper flakes.
Cover and cook on low for 6 hours.
Notes
While fresh tomatoes can be used, many cooks actually prefer canned tomatoes for marinara sauce. Not necessary, but for extra flavor sauté your onions, garlic, in a bit of olive oil before adding them to the slow cooker. This helps to release their flavors and sweetness.One of the benefits of a slow cooker is the ability to slowly simmer the sauce, allowing the flavors to develop and meld together. A low and slow cook time is best for marinara sauce.If using fresh herbs near the end of cooking to keep their flavors bright.A small amount of sugar helps balance might balance the acidity of the tomatoes. If you prefer a smoother sauce, use an immersion blender to puree the sauce to your desired consistency once it's done cooking.BONUS TIP: A tablespoon or two of tomato paste can help thicken the sauce and deepen the tomato flavor.