Step 1Peel the mangoes, seed them and dice the flesh. Don't cut too close to the seed because the flesh there is extremely fibrous and will not puree. You should have about 4 cups. Place the fruit in a bowl with the sugar and stir to combine. Set the fruit aside 30 minutes to macerate, stirring occasionally.
Step 2Heat the ginger, milk, cream and salt over a medium flame in a small saucepan just until warm. Remove from heat and cover. Set aside 30 minutes to steep.
Step 3Place the fruit in a blender and strain the cream mixture over the top, discarding the ginger. Puree until smooth. The mixture will be slightly thinner than a milkshake. Pour into a bowl and chill for 30 minutes.
Step 4Freeze in an ice cream maker according to manufacturer's instructions. The mixture will get to the texture of soft-serve ice cream. Spoon it into a container, cover and place in the freezer for another hour to ripen. Serve immediately. If the ice cream is left overnight, it may become icy, in which case you should allow it to warm slightly outside the freezer before serving.