In a small bowl dissolve the starch in a cup of cold water until there are no more lumps.
In a medium size saucepan add the dissolved starch, sugar, and 1 more cup of water on medium-to-low heat and cook uncovered for 10-15 minutes, stirring frequently.
Reduce the heat to low, add butter, almonds, saffron and cardamom.Stirring constantly for about 10 minutes, or until the mixture is smooth, well blended and thickens. Reduce the heat to low and cook for another 10 minutes.
Add orange blossom water in the last 10 minutes of cooking.
Remove from the heat and pure in to an individual serving bowl and let it set at room temperature before cooling it in the fridge for an hour.
To serving garnish with pistachios and dried rose petals.