Warm the Milk gently in a saucepan until tepid—do not let it boil. Stir in the Granulated Sugar until dissolved, then remove from heat and stir in the Rose Water. Let the milk cool until just warm.
Prepare a shallow glass or ceramic baking dish. Place one Güllaç Leaves sheet in the dish, fitting or gently tearing it to cover the base if needed, and pour just enough of the warm milk over the sheet to soak it through.
Repeat layering a few more soaked Güllaç Leaves sheets to form the first tier (usually 2–3 sheets), pouring milk over each sheet so they are thoroughly moistened but not swimming in liquid.
Sprinkle a layer of coarsely chopped Walnuts and some crushed Pistachios over the sheets, then continue alternating soaked Güllaç Leaves and nut layers until you’ve used most of the leaves, reserving enough milk to finish. Press gently to settle the layers.
Pour the remaining milk evenly over the top layer so the sheets are fully saturated, cover the dish with plastic wrap, and refrigerate for at least 2–4 hours (or overnight) to allow the flavors to meld and the dessert to set.
Just before serving, scatter the top with fresh Pomegranate Arils and an extra pinch of chopped Pistachios and Walnuts for color and crunch. Serve chilled in slices or spooned into bowls.
