Pour cream and milk into saucepan set over medium-high heat. Add the salt and saffron, bring to boil, remove from heat, cover and let steep for 30 minutes. Strain through a fine sieve into a 4-cup glass measuring cup, wipe out the saucepan with a paper towel, and return the infused cream to the saucepan.
Put the egg yolks in a medium mixing bowl set over another bowl filled half way with hot tap water. Whisk the yolks until they are lukewarm, 90–100 degrees, this will just take a minute or two, then remove the bowl from the water.
Add the sugar to the cream and bring back to a boil. Remove saucepan from heat and immediately pour a gradual stream into the egg yolks, whisking constantly for a minute. This will cook the egg yolks, an instant-read thermometer will register 170–180 degrees. Whisk for another minute to slightly cool the mixture and pour through a fine sieve into a 4-cup glass measuring cup. Stir in the rosewater. Refrigerate overnight for best results.
Process in an ice cream maker according to the manufacturers instructions. Enjoy soft serve or transfer into a container and freeze until firm.