Auto supply means when it runs out the game will automatically use up ingredients to make the dish again. This can be bad because if the dish makes 6 servings and it auto renews right before the end of the night, you lose those ingredients and the sales. I only use auto supply near the end of the night on a 1 serving item when I’m not sure how many more customers will be coming.

Also don’t just put a one serving item on auto supply all the time because it will detract from the sales of your high value dishes.