Looking at Sainsbury's website, Bisto gravy granules don't look too bad in terms of carbs:
Per 50ml Portion as prepared
Carbohydrate 2.0g
However just have a look at the ingredients:
Potato Starch, Maltodextrin, Palm Oil, Salt, Wheat Flour (with added Calcium, Iron, Niacin, Thiamin), Colour (E150c), Sugar, Flavourings (contain Barley), Flavour Enhancers (E621, E635), Emulsifier (E322) (contains Soya
One of the key things about Bootcamp is that we try to avoid processed/artificial ingredients as much as possible. So this would really rule Bisto Gravy Granules out!