Take agar agar powder in a bowl.
Add water to it and stir.
The agar agar will be dissolved. Keep aside.
Take chilled full fat cream in a bowl. (I have put the bowl and the blades in the freezer couple of hour before whipping). Start whipping with an electric beater on low speed for 4 minutes.
The cream will start to become thick. Add the icing sugar to it around 1/4 cup.
Beat on medium speed for 4 minutes. Soft peaks will start to form. Now beat on high speed for another 4-5 minutes.
The cream will become thick and have stiff peaks. Cover and refrigerate till in use,
Now take mango pulp in a pan. Add 1/4 cup of sugar and melted agar agar. Mix well.
Let the mixture come to boil and everything is dissolved well. Remove from heat. Add lemon juice and let the mango mixture cool.
Now take the whip cream and add mango mixture to it. (leave 1/2 cup of mango mixture aside to be used as a glaze).
Gently fold the mixture till everything is mixed well.
Take the container or glasses in which the mousse is to be set. Fill first with the prepared cream and mango mixture. Now top with the prepared mango mixture glaze.
Set in the freeze for 5-6 hours. Remove from the refrigerator and garnish with cherry or blueberries or mint leaves or mango cube or dry nuts.
Serve the mango mouse chilled.