As with most foods, we'd always recommend trying to prepare your gravy at home, which means you're able to control what goes into it.
Homemade gravy is typically made by taking the drippings from a roasting pan (i.e. the browned juices and fat from your meat) and adding cornstarch / flour and water until the sauce thickens into a gravy.
On average, 2 tbsp of flour or cornstarch are needed to make approximately 2 cups of gravy.
This means that in 2 cups of gravy, there will be around 18g of carbohydrates (just over one serving of complex carbohydrates).
If you have 4 tbsp of gravy (or 1/4 of a cup) with your meal, this would equal ~2.5g of carbohydrates, only 1/6 of a complex carbohydrate serving.
While homemade gravy would be ideal, sometimes this isn't always possible, and gravy granules are the next best option.
Shop bought gravy granules can often contain added sugar, so be sure to check the ingredients list for this.
Instead of using flour or cornflour to create gravy granules, manufacturers tend to use potato starch. Different ingredients and preparation methods means the carbohydrate content of gravy granules will vary between brands. In order to get an accurate measure, we'd recommend checking the food label.
Overall, the carbohydrate content for gravy granules is usually similar to homemade gravy (~2.5g per 4 tbsp of prepared gravy).