Put the bowl of your ice cream maker in the freezer.
Whisk the yolks and sugar together until pale yellow.
Warm the milk, rose water, and vanilla until it just lightly simmers.
Temper the egg/sugar mixture with the milk/vanilla mixture.
Return to the sauce pan and cook until thickened, stirring slowly and constantly. It should get to 170F.
Remove from heat. Add the broken down or ground saffron into the mixture. Add the cream. Chill in the refrigerator overnight.
The next day, add your chilled ice cream to the ice cream maker. Churn (stir setting) until it is the thickness of soft serve ice cream, 18-22 minutes. While churning, you can add pistachios if that is your preference.
Transfer to a container you can freeze, cover with parchment paper (optional), and freeze at least 4 hours.
Want more saffron flavor? Add an extra ¼ teaspoon of saffron. Want it more rose-y? Add a few drops of rose flavor. Do not add more rose water or it will change the consistency of the ice cream.Cover the ice cream with parchment paper for a longer lasting smooth, soft texture.Beware of saffron knock-offs. You will know it is real if you crush it between your fingers and it turns your fingers yellow.