Caramelise 40 g sugar in a small pot. Deglaze with red wine, add port wine. Boil down at medium heat for about 30 minutes to a syrup.
Bring milk and 50 g sugar to the boil, add rice. Reduce heat and cook for about 30 minutes while stirring.
Cut the mango off the stone. Peel and slice the flesh. Whip cream until stiff.
Fold the cream into the cooked rice pudding. Arrange rice in deep plates, cover with mango and drizzle with port wine sauce.