Transfer to the tin and, using the back of a spoon, press the mixture evenly into the base. Refrigerate for 15–20 minutes or until firm. Place the chocolate and oil in a small bowl and mix to combine.
Add the chocolate and mix until evenly distributed ... but be aware that for this recipe 250g/9oz of additional ingredients is the limit – anything above this will start to affect the texture ...
Tahini comes in two main types light (AKA white or hulled) and brown. Brown tahini is darker in colour and has a more bitter taste. Light tahini is best for this recipe and is now widely available.