01 -
Add meatballs, mushrooms, onion, garlic, and butter to the slow cooker.
02 -
Whisk flour with 4 tablespoons of water until smooth.
03 -
Mix remaining ingredients with the flour mixture, then pour over meatballs in the slow cooker.
04 -
Cover and cook on high for 2-3 hours or on low for 4-6 hours. The sauce will thicken upon cooking, and the meatballs should reach at least 165℉.
05 -
Serve over mashed potatoes, noodles, or mashed cauliflower for a lower-carb option.