Melt the butter in a small pot over medium heat.
If possible use a muffin/bun tray. Using an egg brush spread melted butter into each hole.
Airate and separate the filo shreds if stuck to each other. Place the shredded filo into a bowl and pour the remaining melted butter on top. Mix well with your hands or two forks without squeezing and until all the butter is well combined with all the filo.
Fill each muffin/bun tray hole half way with shredded filo. Press down firmly with the help of the back of a glass or similar.
Sprinkle coarsely chopped walnuts on the filo as the next layer.
Cover the top with shreded filo again. Press down again with the back of a glass or similar.
Bake in a preheated oven at 170° Celsius until golden and crispy. Should take about 30-40 minutes.
When you take out the muffin/bun tray out of the oven. Wait for a minute. Then gently take out each bun using a spoon. Either using the same side or turning them upside down, transfer to a serving dish.
The syrup should be at room temperature by now. Using a ladle pour syrup on top of each bun.
Garnish with ground pistachio.
Set aside for half an hour and serve while still warm or chilled.