Place 1 pastry sheet in well-buttered baking pan and brush with butter. Place second pastry sheet on top of the first and butter again. Repeat until 6 layers of buttered pastry sheets have been built up.
Mix walnuts or almonds, breadcrumbs, sugar, cinnamon and cloves. Sprinkle top pastry sheet thick with walnut mixture and place two buttered pastry sheets over this. Repeat in same manner until all ingredients have been used, ending with 6 pastry sheets.
Brush top with remaining butter and trim edges with sharp knife. Cut diagonal lines the length of the pan to make diamond shaped pieces. Sprinkle with water.
Bake in moderate oven for about 1 hour or until golden.
Prepare syrup: boil sugar, water and lemon juice for 10 minutes. Pour hot syrup over cooked baklava. Allow to stand several hours before serving.