How to Make It
Toast saffron in a small, dry skillet over medium-high until it is dry and a shade darker, 30 seconds to 1 minute. Remove from heat. Transfer toasted saffron to a small plate, and crush it into a powder with the back of a spoon.
Whisk together crushed saffron, milk, cooked rice, uncooked rice, and cardamom in a medium saucepan. Bring mixture to a boil over medium, whisking to break up any lumps of rice. Reduce heat to low, and simmer, covered, stirring occasionally, until thickened and smooth, about 25 minutes. Stir in cream and sugar. Remove from heat.
Serve warm like a sweet risotto, or chill, stirring in a bit more milk before serving to soften the texture, if desired (the pudding will stiffen a bit when chilled). Top servings with pomegranate arils and pistachios.