Line an 8-inch baking pan with a sheet of parchment paper or use a disposable aluminum pan.
FOR THE BAKLAVA
Toast both kinds of walnuts separately about 8 minutes, or until lightly browned. Coarsely chop the regular walnuts so they are similar in size to the black walnuts (our tester also chopped the black walnuts more finely). In a small mixing bowl, toss both kinds of walnuts with the sugar, cinnamon and nutmeg. Brush an 8-inch square pan with some melted butter.
Preheat oven to 350°. Cut 18 (8-inch) squares of phyllo dough. Cover the squares with a damp towel to prevent them from drying out.
Lay a piece of phyllo in the bottom of the buttered pan and brush it generously with melted butter. Lay another layer of phyllo dough over this and brush it again, generously, with melted butter. Repeat the process until you have 8 buttered layers. Some pieces of the phyllo may need to be trimmed or patched.
Make a layer of nuts with ½ of the nut filling (about 1½ cups). Top the nuts with 4 sheets of phyllo, brushing generously between layers. Spread the remaining nut mixture onto the top buttered phyllo sheet. Top the nuts off with 6 more layers of phyllo (with butter between the layers) to finish it.
Before baking, cut the baklava into 4 (4-inch) square quarters. Then cut each square on the diagonal into 4 more pieces.
Place the pan on a baking sheet and bake for about 45 minutes. The baklava will start to turn light golden brown. Lower the oven heat to 300° and bake for 20 minutes more.
FOR THE SYRUP
While the baklava is baking, make the syrup by combining the water, sugar, honey, cinnamon sticks and cloves in a small saucepan. Bring the mixture to a boil over high heat and then reduce the heat to medium. Stir to help dissolve the sugar, and continue cooking at a brisk simmer for 20–40 minutes (our testers found it took longer than the suggested 20 minutes for the syrup to reduce), until the syrup thickens to about 1½ cups. Stir in the lemon juice, and keep the syrup warm.
When the baklava comes out of the oven, pour the warm syrup evenly over the pan. Cool completely. Cut through each marked piece and carefully lift from the pan. If you are not using a disposable pan, pull the whole parchment paper from the pan and then serve.
Recipe from the book Spice: Flavors of the Eastern Mediterranean by Ana Sortun ©2006. Reprinted by permission of William Morrow, an imprint of HarperCollins Publishers.