Place half-and-half, vanilla seeds, cinnamon sticks, cloves, star anise, and saffron in a medium saucepan and heat until just scalded. Set aside to cool for 1/2 hour. Place egg yolks and sugar in a bowl and whist together. Gradually add cooled half-and-half mixture to egg-and-sugar mixture, whisking continuously. Then pour back into saucepan and cook, stirring constantly, over medium heat until mixture thickens. Immediately strain into the melted chocolate and whisk well. Add rose water and chill. Freeze in an ice cream machine, following manufacturer's directions. Makes approximately 1 1/2 quarts.