A package of onion soup mix only has 4 g of carbs with less than 1 g of net carbs. A serving size in one package is 8. That is only 0.5g of carbs per serving. This keto beef stroganoff recipe serves 10, of the total carbs in this recipe coming from the onion soup mix are only 0.4g.  I consider that a low-carb onion soup mix!