In a saucepan, bring all the ingredients to a boil, and stir until the sugar has completely dissolved. Let cool.
With the rack in the middle position, preheat the oven to 300°F (150°C). Butter an 8-inch (20 cm) square, straight-edged baking pan.
In a food processor, finely chop the pistachios and almonds (see note). Transfer to a bowl. Stir in the sugar and cinnamon. Set aside.
On a work surface, brush 3 sheets of phyllo dough with butter, laying them one on top of the other. On the lower third of the dough, spread a third of the nut mixture (about cup/160 ml) in a thin strip running the entire length of the dough, up to 1/2 inch (1 cm) from the edges. Roll tightly while pressing down on the dough to form a long roll. Cut the roll in half and place in the prepared pan. Trim the ends if needed. Repeat the process to make two more rolls. Once all the rolls are in the pan, brush the surface with butter.
Bake for about 1 hour or until the pastry is golden brown.
Remove from the oven and pour the cooled honey syrup over the entire surface of the baklava, removing the lemon peel, cinnamon stick and clove. Let cool at room temperature, about 6 hours or overnight.
On a work surface, cut each roll into three pieces. Baklava will keep in an airtight container at room temperature for up
to 10 days.
The nuts should be quite finely chopped. It’s better to have a bit of nut powder than to have overly large pieces.