If the carbs are coming from the chicken, the bacon, the cream, and the cheese, don’t worry about them too much. If they are from added ingredients, that’s a different matter. Avoid sugar-cured bacon, of course, and aged cheeses should have very little galactose or lactose in them. Heavy cream is entirely fat, so no sugar, unless they added maltodextrin for some stupid reason.
Remember that the point of the diet is to lower insulin, which entails lowering carbohydrate intake. Ketones are the sign that insulin is low enough to be beneficial. The more insulin-sensitive we are, the more carbohydrate we can safely eat, so the 20 g/day limit is somewhat arbitrary. Your personal limit may vary. We recommend sticking to the 20 g/day limit for the first few months; after one is fat-adapted, it then becomes safe to experiment a bit.
The word among the original members of the forums was that the Dudes really wanted to tell people to eat no carbs at all but were afraid that would frighten people away. So they settled on 20 g/day as a level of intake that will work well for most people. (It’s also the limit recommended by Dr. Phinney, one of the original researchers in the field.)