BastaniPersian Saffron Ice Cream

Name: Bastani/Persian Saffron Ice Cream
Ingredients: Frozen Cream; 1/2 pint heavy cream; the zest from a medium lemon; Saffron and Rose Water Custard; 7 egg yolks; 2 cups granulated sugar; 1 tablespoon cornstarch; 2 cups whole milk; 2 and 1/2 cups heavy cream; 1/2 teaspoon ground saffron; 1/4 cup rose water; 1 pinch salt; 5 tablespoons whole milk ricotta; 1 teaspoon lemon zest; 1 cup dry roasted and salted pistachios nutmeats (for sprinkling on at the end)