Wash, cut and peel mangoes. Puree 3 mangoes and finely chop the fourth one and keep aside for later use.
Whip the cream. For steps on how to whip cream click here. Keep refrigerated until further use. Take milk in a bowl, add pudding mix and beat till it gets thickened.
Add mango puree, some of the mango pieces and fold-in with whipped cream and then into the pudding mix.
If you don't have Jell-O Pudding (as it not available in India or you don't want to use it, just skip the step of making pudding, whip the cream and fold in mango puree and pieces. Adjust sugar in the cream as per the sweetness of mangoes.
Transfer the mousse into individual mousse glasses or serving dishes and keep in refrigerator to chill.
Take out just before serving, garnish with more mango pieces and enjoy!!