Melt butter in a nonstick pan over medium heat. Add chopped kataifi and toast until deeply golden and nutty-smelling. Let cool completely.
In a bowl, mix cooled kataifi with pistachio cream, tahini, and a pinch of salt. Stir until combined and scoopable.
Melt your chocolate: either temper it for a shiny, snappy finish, or melt with coconut oil for a simpler method that requires refrigeration.
Pour about one-third of the melted chocolate into each mold. Tilt to coat sides and chill until firm.
Spoon in the filling, pressing gently to flatten and reach the edges.
Cover with remaining melted chocolate, smooth the bottom, and refrigerate for at least 30–45 minutes until fully set.
Once firm, unmold the bars. If using tempered chocolate, they can be stored at room temperature. Otherwise, keep them refrigerated.
