01 -
Heat heavy cream over medium heat just to a simmer without boiling. Pour over chopped dark chocolate in a heatproof bowl and let stand for 1 minute. Stir gently until an even, glossy mixture forms. For added shine, incorporate unsalted butter at this stage, if desired.
02 -
Spoon the warm ganache into 6 small serving glasses, filling each about one-quarter full. Refrigerate the glasses to chill the ganache while preparing the mousse.
03 -
Optional for enhanced color: Blanch pistachios by simmering for 1 minute, transferring to an ice bath, and peeling skins. Blend peeled pistachios, granulated sugar, salt, and vanilla extract in a food processor until finely ground, adding a splash of cream if necessary to reach a smooth paste.
04 -
Using an electric mixer, whip cold heavy cream until soft peaks form. In a separate bowl, beat softened mascarpone or cream cheese until completely smooth. Combine the pistachio paste with the mascarpone until evenly incorporated.
05 -
Gently fold the whipped cream into the pistachio-mascarpone mixture in two additions, maintaining as much volume as possible for a light texture.
06 -
When the ganache layer is firm, carefully spoon or pipe pistachio mousse over the ganache, filling the glasses fully. Level the tops, cover loosely, and refrigerate for at least 2 hours to set.
07 -
Just before serving, garnish each portion with chopped roasted pistachios, chocolate curls, and, if desired, a sprinkle of gold dust or sea salt flakes. Serve chilled.