Put the oil in a large skillet and heat to medium-low.
Add the onion and sauté until it is translucent. About 10 minutes.
Add the garlic and cook 5 more minutes. It really does make the sauce taste better to sauté first.
Add all of the ingredients to the slow cooker except the frozen meatless crumbles.
Cook on low for 6 to 8 hours adding the frozen meatless crumbles the last two hours.
If you want to cook on high then cook 3 to 4 hours adding the frozen meatless crumbles the last hour.
IF FREEZING:Let cool to room temperature. Package in rigid sided containers as defined in my article How to Prepare Food for the FreezerI freeze it in freezer jars and it keeps the sauce neat and contained in the freezer.PICTURETO PREPARE AFTER FREEZING:Remove from the freezer and put in the refrigerator overnight because it is a pretty solid mass and will take longer to defrost.THE NIGHT OF SERVING:Put all in a large saucepan and heat o boiling and then turn down the heat for about 5 minutes.Cover with a splash guard to play it safe and keep everything cleaner on the stovetop.