In a saucepan, combine milk, sugar, and salt. Heat over medium flame until sugar dissolves (do not boil).
Remove from heat. Stir in heavy cream, rose water, vanilla extract, and pistachio paste. Mix until smooth.
Let the mixture cool to room temperature, then refrigerate for 1–2 hours to chill thoroughly.
If using an ice cream maker: Pour chilled mixture into the machine and churn according to manufacturer instructions until creamy. If no ice cream maker: Pour into a freezer-safe container and freeze. Every 30–40 minutes, stir vigorously with a fork to break ice crystals until smooth (repeat 4–5 times).
Scoop into bowls or cones. Garnish with chopped pistachios and a drizzle of rose syrup if desired.
