This slow cooked spaghetti sauce does have a secret ingredient: carrots! Carrots are a great addition to spaghetti sauce because their natural sweetness gives the sauce a rich taste. They also help cut the acidity.  I chop my carrots fine so they aren’t really recognizable by picky eaters. You can also grate them if you prefer. Finally, you could strain them out of the sauce before you eat, if you want, but we never do.