Preheat your oven to 350°F (175°C). In a baking dish, separate the kataifi strands and drizzle melted unsalted butter over them, ensuring even coating. Bake for 12-15 minutes until golden brown and crispy. Allow to cool completely on a wire rack.

Melt white chocolate in a microwave-safe bowl, heating in 30-second intervals, stirring until smooth. Add pistachio butter and a pinch of sea salt, mixing until well combined. Adjust consistency with vegetable oil if too thick.

Finely chop the cooled kataifi into small pieces and fold into the pistachio mixture, ensuring even distribution.

Form walnut-sized balls from the mixture, place on a lined baking sheet, and refrigerate for at least 30 minutes.

Melt dark chocolate in a microwave-safe bowl, temper by stirring and allowing it to cool slightly.

Dip each ball into the dark chocolate until fully coated, let excess drip off, and place back on the baking sheet. Sprinkle with chopped pistachios.

Let the chocolate balls set at room temperature for about 15 minutes, then store in an airtight container.