Put the cold chopped butter, flour, salt and icing sugar into a food processor. Process until the mixture looks like sand. Beat the egg & milk well before adding all but 1 Tablespoon and blitz again. If it doesn't come together and form a ball of dough after being 1 minute ad the remainder of the liquid.
Pour onto a bench and push together. Wrap and refrigerate till cold ( 10 minutes or till needed). Roll out to fit your tart case. Fill with baking beans and bake for 15 minutes before removing the beans fixing any holes and baking till golden
Put the filling ingredients into a food processor and process till smooth.
Pour into the tart case & bake for 30 minutes. Test with a skewer, if it is hot and the middle of the tart feels like it is becoming firm remove from the oven. It could take another 10 minutes or so depending on your oven.
Cool the tart completely. Put the cream in a small pot or the micro wave and heat till just under boiling point. Take off the heat and cool a touch before adding the chopped chocolate and stir till smooth. Pour over the tart case and tap to spread finishing with a palette knife
I have decorated with cocoa, praline and macadamia nuts