Melt chocolate in a double boiler

Whisk egg yolks and add sugar slowly until incorporated

Split vanilla bean in half length wise and scrap into cream

When chocolate is melted set aside and let cool about 5 minutes

Add egg mixture to cream

Add chocolate to egg and cream mixture and whisk to combine then add pistachios or nuts of choice

Pour into muffin tins or small bread pan lined with plastic wrap then freeze for upto 2 to 3 hours to set.