For the crust, crush about 200 g of plain biscuits and mix with 80 g of melted butter until it holds when pressed; pack into a 22-24 cm tart tin and bake at 170°C for 10 minutes. While it cools, heat 250 g of heavy cream (35%) just to a simmer, pour it over 250 g of chopped dark chocolate (55-70%), wait one minute, then stir from the center outward until glossy. A spoon of honey or glucose (about 20 g) keeps the ganache silky after chilling. Pour into the shell and let it set at room temperature for two hours, or chill for 30-40 minutes if impatient. Serve slightly cool-not fridge-cold-so the texture is soft on the fork. If the ganache splits, add a splash of warm cream and stir gently; if the surface looks dull, warm a knife under hot water, wipe dry, and smooth the top in one confident pass. A few flakes of sea salt and a thin ribbon of cream are all the drama it needs.