...It is especially important in a chip buttie, otherwise the chips and melted butter ooze out.

You mean, you take the healthy potato, cut it, deep fry it in fat, then put it on bread and drench it in melted butter? Exactly what is your cholesterol count anyway? Or is it, as you say, "a luxury food reserved for very rare moments of comfort deficit" and not eaten on a regular basis?

And, by the way, my favorite way to have french fries, yeah, I know...the cholesteral thing is dipped in blue cheese dressing. Especially good when served with the spicy chicken wings we have here in Buffalo. They are NOT called Buffalo wings. Buffalos do not have wings, folks!