Whip cream, 1/2 cup sugar, rose water, coriander, and cardamom until stiff peaks form. Refrigerate.
Beat egg whites in a glass or metal bowl until foamy. Gradually add 1/4 cup sugar and continue whipping until stiff peaks form. Lift your beater or whisk straight up: the egg whites will form sharp peaks. Fold egg white mixture into cream mixture until combined. Pour mousse into individual dishes or a serving dish and refrigerate at least 6 hours or overnight.