Blend the Mortadella with the spreadable cheese. Add the milk to obtain a creamy consistency. Using a cup, cut circles from the sandwich bread, around 15-20cm diameter. Lightly toast them in the oven. Once the bread is cold, cover it with the Mortadella mousse, creating half a sphere. WIth an icing bag, put more mousse on top, creating a brain effect. For a better effect, decorate with ketchup. Put it in the fridge to rest. Meanwhile, prepare the sandwich bread by cutting it into scary shapes. Lightly toast it and spread the black olive paste. Serve the brain cold, accompanied by crostinis on which you can spread the mousse.
