Add some of the milk into a pot and dissolve the cornstarch
Add the rest of the milk and cream and turn the heat on
Add the mastic and the orange blossom and rose water
Add the sugar
Cool, stirring frequently for 5-7 mins till the milk thickens
Remove, cool and place in a bowl or small ramekins to set in the fridge for 6 hrs to overnight
When ready to serve, garnish with the crushed pistachios, slivers of almonds and pistachios and pomegranate seeds