In a medium pot, whisk together milk, heavy cream and 1/2 cup sugar. Allow to warm up but not boil. Make sure sugar dissolves and keep warm.
Next, grind 1 teaspoon of sugar and pinch of saffron threads in a mortar. Grind until the saffron breaks down. You still may see some threads leftover.
Add sugar and saffron mixture and the rose water to cream mixture. Mix to incorporate.
On low heat, add the egg yolks slowly while whisking at the same time. Continue whisking and keeping on low heat for about 8-10 minutes until mixture has thickened slightly.
Once everything is mixed well, take the cream mixture and strain it with a sieve (or fine mesh strainer) over a bowl to remove leftover saffron threads.
Place mixture in a well-sealed container and refrigerate for at least 4 hours to overnight. The mixture has to be chilled before churning.
Once mixture is chilled, pour into ice-cream maker. I am using the Kitchen-Aid Ice Cream attachment. For this attachment, I placed the setting at 1-2 and let it turn for 20 minutes. At the last 2 minutes, add the chopped pistachios.
It will be very soft at this point so place in container and in the freezer for at least 2 more hours until ready to serve.