Chocolate baklava

Method

1. Heat the oven to 160C/140C fan/gas 3. Mix the pecans with the chocolate, tahini if using, cinnamon and 50g of the granulated sugar and divide into 3 equal amounts.
2. Melt the butter in a small pan over a very low heat until all the milky-looking solids have settled at the base of the pan. Slowly pour the clear butter into a bowl and discard the cloudy liquid left behind in the pan. You should have about 200g of clarified butter.
3. Unroll the sheets of filo pastry, putting them together in one big stack. Using the base of the roasting tray or baking dish as a template, cut around the dish so that the pastry sheets fit snugly into the base. You should have 28 sheets so you might need to slightly overlap and join together some of the larger trimmings to make them the right size. Stack them all up and set aside, covered with a slightly damp tea towel.
4. Brush the base and sides of the tin with some of the clarified butter. Put 1 layer of pastry in the base of the tin, then brush evenly with more butter. Repeat until you have layered up 10 sheets of pastry.
5. Scatter one third of the pecan/chocolate mixture in an even layer over the top of the pastry, then cover with 3 more sheets of buttered filo pastry. Repeat once more, then scatter over the remaining pistachio/sugar mixture and cover with the remaining 12 sheets of the filo pastry, buttering between each sheet.
6. Using a large, very sharp knife, cut the baklava into portion-size pieces. To do this, cut it lengthways into 4 or 5 evenly sized strips, then across at an angle to make small diamond-shaped pieces. Drizzle over any remaining butter.
7. Bake the baklava for 1 hour until crisp and richly golden. Meanwhile, make the syrup. Put the remaining 550g sugar, cloves, cinnamon stick and 350ml water in a pan and stir over a low heat until the sugar has dissolved. Bring to the boil and cook until it reaches 107-108C on a sugar thermometer. Remove the whole spices with a slotted spoon (discard), add the lemon juice and set to one side.
8. Just as you bring the baklava out of the oven, bring the lemon syrup back up to the boil. Increase the oven temperature to 180C/160C fan/gas 4. Run a sharp knife along the cuts to make sure each piece is separate then pour over the boiling syrup. Return to the oven for 5 minutes.
9. Remove the baklava from the oven and leave it to cool completely. Run a knife along the cuts and then carefully remove from the tin, a piece at a time, using a palette knife.