OPTION 1: Saute onion, carrots, celery, and garlic in a pan with a little oil or butter. Place that and the rest of the ingredients except honey and salt (and meat, if using) in the slow cooker.
OPTION 2: Place all ingredients except honey and salt (and meat, if using) in the slow cooker.
Cook on high for 3-4 hours, or on low for 6-8 hours, until carrots are soft.
Use an immersion blender to puree the sauce, or blend it in batches in a countertop blender (only fill the blender halfway - hot liquids expand then explode and make a terrible mess. Ask me how I know). You can also leave the sauce as is! Whatever works for you.
Stir in salt and honey. Taste and adjust amounts as needed. If using meat, stir that in as well.
TO FREEZE: Let sauce cool, then pour it into plastic freezer bags, plastic containers with lids, or glass jars. Leave a little space at the top to let the sauce expand in the freezer. Seal, then store in the freezer. Thaw overnight and reheat to serve.
Easy, Cheap, Slow Cooker Marinara Sauce https://www.cheapskatecook.com/easy-marinara-sauce/