A brownie full of autumnal textures and flavours. Tahini makes a delicious addition to brownies, nutty and creamy, and adds a beautiful sepia swirl.
375g dark chocolate, broken into pieces
500g caster sugar
Seeds of 1 vanilla pod
225g plain flour
Pinch of salt
200g cooked and shelled chestnuts, roughly chopped
200g walnuts, toasted in the oven for about 12 minutes, then roughly chopped
3 tablespoons light tahini
Line a baking tin with parchment and preheat the oven to 180°C/ Gas Mark 4. Put the butter and chocolate into a large bowl and set it over a pan of boiling water until they have melted. Put some cold water in a basin and carefully sit the bowl in it for a few minutes to cool, stirring the mixture occasionally.
Beat the eggs, sugar and vanilla together and then beat them into the cooled chocolate mixture. Stir in the flour, salt, chestnuts and walnuts. Pour the mixture onto the baking tray and smooth over the top. Blob the tahini onto the top and use the spoon or a knife to make swirls. Bake for about 35–40 minutes, or until the wobble is minimal and the top has started to crack. Remove, leave to cool completely, then cut into 24 squares and serve.