Recipe inspired by @eaturselfskinny
Optional: If adding onion, heat a skillet on medium low heat. Add oil and once warm, add in chopped onions. Saute until onions are caramelized. Transfer to slow cooker.
In a 6-quart slow cooker, add all ingredients and mix with a big spoon.
Cover slow cooker and place on low for 6-8 hours. Enjoy!