[Type 1] Milk/white chocolate - how do you do it?

Like everyone else, I enjoy the occasional chocolate treat but I seem to always get a mixed bag of results. Last night bg sitting at 6.4 so I have a bit (40g total carbs serving) take the 4 according units and this morning my bg is at 14 D: the only thing I can think of I've done wrong is beforehand I ate 3 babybel cheeses and 2 peperami and that the fat/protein from that slowed down the chocolate to the point of it overlapping my bolus? I've been at my local diabetic clinic recently and asked about taking bolus for protein as I know some people do but was just told in the UK we don't advise that. Is that really the case here in the UK?