These are the ingredients;
Vegetable Oil, Potato Starch, Maltodextrin, Dried Glucose Syrup, Whole Milk Powder, Corn Flour, Sugar, Yeast Extract, Milk Proteins, Dried Parsley, Flavourings (contain Milk, Wheat), Stabilisers (E340, E452), Emulsifier (E322) (Soya), Flavour Enhancer (E621), Spice&Herb Extracts, Onion Extract
You wouldn't add any of the things in bold if you were cooking Dukan from scratch, so you really shouldn't add them just because they come ready mixed.
But you could add dried parsley, salt, pepper and a little cornflour blended into skimmed milk, for the same result and only one tolerated item.