For a professional look which eliminates small imperfections from the surface (like in the photograph), remember to pour the mixture into the tart through a very fine strainer.
Remarks
To decorate, you can sprinkle it, when cold, with a little cocoa powder, icing sugar and/or chocolate chips.
You can also add a delicious citrus fruit flavour to the chocolate, by adding a fine layer of candied grapefruit peel before pouring in the chocolate.