Use homemade or good quality rose petal jam to flavor this light mousse.
1 1/2 teaspoons unflavored gelatin
1 cup whole milk
1/2 cup sugar
4 tablespoons rose water or more, to taste
1 1/2 cups full-fat Greek yogurt
3/4 cup chilled heavy cream
Rose Petal Jam
3 tablespoons coarsely chopped pistachios
Fresh or dried rose petals
Sprinkle the gelatin over 1/4 cup milk in a small bowl and let stand for 2-3 minutes to soften.
In a saucepan, over moderate heat, bring the remaining milk and all the sugar to a boil. Simmer and stir until the sugar dissolves. Add the gelatin mixture and turn off the heat. Stir vigorously on the stove until the gelatin dissolves completely. Pour the mixture into a metal bowl, add the rosewater and stir well to mix. Place it over an ice-water bath to cool rapidly.
Let cool for 15-20 minutes, stirring often until cold. Add the yogurt and whisk to incorporate. Taste, and if you like, add more rose water.
Whip the heavy cream with a hand-held mixer until it gets a good amount of body. Fold the cream into the cooled milk-yogurt mixture. It must be completely incorporated. Cover with plastic film and refrigerate for about 30 minutes, or until it starts to set.
You can let the cream set overnight in the bowl. Take out of the refrigerator and stir the cream a few times before assembling the mousse.
Assembling the mousse:
Add 2 tablespoons of rose petal jam at the bottom of each serving glass and then divide the chilled mousse evenly among them. Cover with plastic wrap and refrigerate for 2-3 hours, preferably overnight.
Serve sprinkled with pistachio and decorate with a few fresh or dried rose petals.