Rosewater-and-Saffron Ice Cream (Bastani Irani)

Set a medium bowl in a large bowl of ice water. In another medium bowl, beat the egg yolks until pale, 1 to 2 minutes.

In a medium saucepan, whisk the cream with the milk, sugar, salt and saffron. Bring to a simmer over moderate heat, whisking, until the sugar is completely dissolved. Very gradually whisk half of the hot cream mixture into the beaten egg yolks in a thin stream, then whisk this mixture back into the saucepan. Cook over moderately low heat, stirring constantly with a wooden spoon, until the custard is thick enough to lightly coat the back of the spoon, about 12 minutes; don’t let it boil.

Strain the custard through a fine-mesh sieve into the bowl set in the ice water. Let the custard cool completely, stirring occasionally. Stir in the rosewater and vanilla extract. Press a piece of plastic wrap directly on the custard and refrigerate until well chilled, at least 4 hours.

Pour the custard base into an ice cream maker and freeze according to the manufacturer’s instructions. Transfer the ice cream to a chilled 9-by-4-inch metal loaf pan, cover and freeze until firm, at least 4 hours.

Serve the ice cream in bowls, garnished with dried roses.