This is a bit of a bother to make, but your rewards will be great in fruit mousse heaven.
2-3 ripe 1-pound mangoes
3 ounces (1/4 cup + 2 tablespoons) sugar
2 tablespoons fresh lemon juice
3 1/2 teaspoons unflavored gelatin
2 cups whipping cream
Peel the mangoes and scoop the flesh away from the seeds. You want about 20 ounces of fruit. Purée the flesh and the sugar in a food processor until smooth. Add the lemon juice and strain the mixture through a sieve.
Pour about a third of the purée into a small saucepan, warm it gently, then add the gelatin, stirring it until it dissolves. Pour the mixture into a large bowl and add the rest of the purée. Allow it to cool, stirring it from time to time. When the purée is close to room temperature, whip the cream to soft peaks.
Immerse the bowl of purée in an ice bath. Scrape the bowl with a rubber spatula until you notice the mousse beginning to thicken. When that happens, remove the bowl from the bath and whip the cream the rest of the way to stiff peaks. Whip in the mango purée, then immediately pour the purée in the appropriate mold.
This mousse can be made with any number of fruits, though you might have to adjust the sugar a bit according to the fruit and your taste. Follow the same procedure with 20 ounces (2 1/2 cups) of puréed and sieved raspberries, strawberries, cantaloupe, bananas or blackberries. It also works with poached peaches, apricots, pineapples, kiwis, apples or pears, though you’ll probably need to add a little color to these, since poached fruit bavarians can look a little dull.