You need to look at the calories in the "as sold" column, as the "per portion" column refers to the recipe as listed (and presumably you would be using chicken, which would be free, but I don't know what other ingredients they suggest, or whether they need to be synned).
So it says 331 calories per 100g, and the packet is 48g, so say 165 calories per packet, which would be just over 8 syns (using the 1 syn per 20 calories rule). Presumably it serves four? So that would be 2 syns per portion for the mix.
But please - anyone else feel free to chip in here and dispute my calculations!!