You need the lovely Montezuma‘s dark chocolate with orange and geranium; about 1/4 – 1/3 of a bar per person. Break it up a bit and put it in a nice little bowl. Add a dollop of butter (bigger than a knob; not quite a slice), some double cream and some agave syrup and whack it in the microwave for 45 seconds or so. Mix it around with a fork and pour onto vanilla icecream.
(If you really must, you can keep it in the fridge and re-microwave it the next day.)