How to Make It
Bring sugar, 1 1/2 cups water, and lemon juice to a boil in a small saucepan over medium-high. Reduce heat to medium, and simmer, stirring occasionally, until sugar is dissolved, about 5 minutes. Let syrup cool completely, about 30 minutes; stir in orange blossom water and rose blossom water.
Preheat oven to 400°F with oven rack in bottom third of oven. Generously grease a 13- x 9-inch pan with ghee or butter. Stir together mozzarella and ricotta in a medium bowl until combined; cover and refrigerate until ready to use.
Using your hands, mix together kataifi and melted ghee in a large bowl until combined. Scatter half of the kataifi mixture into prepared pan, pressing firmly with your hands to evenly cover bottom. Dollop spoonfuls of cheese mixture evenly over top, and, using damp hands or an offset spatula, spread in an even layer. Scatter remaining kataifi mixture evenly over filling, and press firmly.
Bake in preheated oven on lower rack until cheese has melted and crust is golden brown, 25 to 35 minutes. Let cool in pan on a wire rack 5 minutes. Invert pie onto a serving platter. Immediately drizzle with enough of the cooled syrup to soak the cake (about 11/2 cups). Sprinkle with pistachios, and serve with remaining syrup.