Grind the roses and cardamom in a spice grinder until the roses are broken into smaller pieces and the cardamom seeds are ground.
In a small saucepan over low heat, toast the cardamom-rose mixture for about 2 minutes, constantly stirring, to bring out the flavor. Once this is done, turn off the heat.
In a small pot over medium heat, combine milk with the other ingredients.
Allow the mixture to boil. Once it boils, turn off the heat and let the pot sit for 5 minutes, covered with a lid.
Remove the pot from the heat.
Strain the milk through a sieve into a cup, then use a milk frother to froth it up before serving hot! Sprinkle with dried rose petals on top if desired.