Into crockpot put:
2 cans tomatoes, either whole or diced
1 can tomato paste (sugar free)
1 small onion chopped
1 carrot, diced
2 stalks chopped celery
2 cloves garlic
Also, whatever you want to get rid of zuchinni, spinach, left over beans, etc.
salt and pepper to taste
dried basil or oregano
1 tablespoon wine vinegar
like my sauce on the spicy side so I add 1/2 teaspoon hot red pepper flakes.
I usually cook it overnight in the crock pot and then use my immersion blender. Let cool and refrigerate. Be sure to refrigerate it as soon as it cools so the sauce won't go bad on you. I have kept it up to a week in the fridge and used it for various recipes.