To fill 20cm tart dish
Crush the digestive biscuits.
Melt 100g of the butter. Pour over the digestive biscuit crumbs and stir well
Tip the biscuit mix into a tart dish, pressing down, to make a compact, firm base
Add the remaining 50g of butter and double cream to a pan, heat to just below boiling point. Take off the heat and stir in the dark chocolate
Once you have a thick gloopy chocolate sauce, pour it on top of the biscuit base, smooth out with the back of a spoon.
Pop in the fridge for 1-2 hours to set
* Serving suggestion, Delicious with a sprinkle of sea salt
